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1. Detection of Very High-energy Gamma-Ray Emission from the Radio Galaxy M87 with LHAASO

Author: Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. C. Chu, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, T. T. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, O. A. Hannuksela, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, C. Huang, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Y. Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, H. B. Jiang, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Khangulyan, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, K. C. Y. Ng, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, L. H. Wan, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, and X. Zuo
Subjects: Active galactic nuclei, High energy astrophysics, Astrophysics, QB460-466
Abstract: The nearby radio galaxy M87 is a very high-energy (VHE) gamma-ray emitter established by observations with ground-based gamma-ray detectors. Here we report the long-term monitoring of M87 from 2021 to 2024 with the Large High Altitude Air Shower Observatory (LHAASO). M87 has been detected by LHAASO with a statistical significance ∼ 9 σ . The observed energy spectrum extends to 20 TeV, with a possible hardening at ∼20 TeV and then a clear softening at higher energies. Assuming that the intrinsic spectrum is described by a single power law up to 20 TeV, a tight upper bound on the extragalactic background light intensity is obtained. A strong VHE flare lasting 8 days, with a rise time of ${\tau }_{r}^{\mathrm{rise}}=1.05\pm 0.49$ days and decay time of ${\tau }_{d}^{\mathrm{decay}}=2.17\pm 0.58$ days, was found in early 2022. A possible GeV flare is seen also in Fermi Large Area Telescope data during the VHE flare period. The variability time as short as 1 day seen in the LHAASO data suggests a compact emission region with a size of ∼3 × 10 ^15 δ cm ( δ being the Doppler factor of the emitting region), corresponding to a few Schwarzschild radii of the central supermassive black hole in M87. The continuous monitoring of the source reveals a duty cycle of ∼1% for VHE flares with a flux above 10 ^−11 erg cm ^−2 s ^−1 .
Published: 2024
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2. Discovery of Very High Energy Gamma-Ray Emissions from the Low-luminosity AGN NGC 4278 by LHAASO

Author: Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, X. Zuo, and The LHAASO Collaboration
Subjects: High energy astrophysics, Gamma-ray astronomy, Low-luminosity active galactic nuclei, LINER galaxies, Blazars, Fanaroff-Riley radio galaxies, Astrophysics, QB460-466
Abstract: The first source catalog of the Large High Altitude Air Shower Observatory (LHAASO) reported the detection of a very high energy gamma-ray source, 1LHAASO J1219+2915. This Letter presents a further detailed study of the spectral and temporal behavior of this pointlike source. The best-fit position of the TeV source (R.A. = 185.°05 ± 0.°04, decl. = 29.°25 ± 0.°03) is compatible with NGC 4278 within ∼0.°03. Variation analysis shows an indication of variability on a timescale of a few months in the TeV band, which is consistent with low-frequency observations. Based on these observations, we report the detection of TeV γ -ray emissions from this low-luminosity active galactic nucleus. The observation by LHAASO's Water Cherenkov Detector Array during the active period has a significance level of 8.8 σ with a best-fit photon spectral index Γ = 2.56 ± 0.14 and a flux f _1–10 TeV = (7.0 ± 1.1 _sta ± 0.35 _syst ) × 10 ^−13 photons cm ^−2 s ^−1 , or approximately 5% of the Crab Nebula. The discovery of VHE gamma-ray emission from NGC 4278 indicates that compact, weak radio jets can efficiently accelerate particles and emit TeV photons.
Published: 2024
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3. The First LHAASO Catalog of Gamma-Ray Sources

Author: Zhen Cao, F. Aharonian, Q. An, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, J. T. Cai, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. Y. He, X. B. He, Y. He, M. Heller, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Z. C. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, T. Ke, D. Kuleshov, K. Kurinov, B. B. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, Jian Li, Jie Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, R. Lu, Q. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, Z. W. Ou, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, A. Sáiz, D. Semikoz, C. Y. Shao, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Q. W. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, K. Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, F. Yang, F. F. Yang, H. W. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, L. X. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and (The LHAASO Collaboration)
Subjects: Gamma-ray astronomy, Gamma-ray observatories, Catalogs, Astrophysics, QB460-466
Abstract: We present the first catalog of very-high-energy and ultra-high-energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory. The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array from 2021 March to 2022 September and 933 days of data recorded by the Kilometer Squared Array from 2020 January to 2022 September. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering decl. from −20° to 80°. In total, the catalog contains 90 sources with an extended size smaller than 2° and a significance of detection at >5 σ . Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ( E > 100 TeV) emission at >4 σ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.
Published: 2024
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4. Further results from DAMA/LIBRA-phase2 and perspectives

Author: R. Bernabei, P. Belli, A. Bussolotti, V. Caracciolo, F. Cappella, R. Cerulli, C. J. Dai, A. d’Angelo, N. Ferrari, A. Incicchitti, A. Leoncini, X. H. Ma, A. Mattei, V. Merlo, F. Montecchia, X. D. Sheng, and Z. P. Ye
Subjects: dark matter, elementary particle processes, scintillation detectors., Atomic physics. Constitution and properties of matter, QC170-197
Abstract: The data collected by the DAMA/LIBRA-phase2 set-up during two additional annual cycles have been analyzed, further investigating the long-standing model-independent annual modulation effect pointed out by DAMA deep underground at the Gran Sasso National Laboratory of the I.N.F.N. by using various different experimental configurations. Including the new results, the total exposure of DAMA/LIBRA-phase2 over 8 annual cycles is 1.53 t·yr and the evidence for a signal that meets all the requirements of the model-independent Dark Matter annual modulation signature is 11.8 σ C.L. in the energy region (1 - 6) keV. In the (2 - 6) keV energy interval, where data are also available from DAMA/NaI and DAMA/LIBRA-phase1, the achieved C.L. for the full exposure of 2.86 t·yr is 13.7 σ. No systematics or side reaction able to mimic this signature (i.e., to account for the whole measured modulation amplitude and to simultaneously satisfy all the requirements of the signature) has been found or suggested by anyone throughout some decades thus far. A preliminary result on the further lowering of the software energy threshold and perspectives are also mentioned.
Published: 2021
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5. Construction and on-site performance of the LHAASO WFCTA camera

Author: F. Aharonian, Q. An, Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and The LHAASO Collaboration
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here.
Published: 2021
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6. Improved model-dependent corollary analyses after the first six annual cycles of DAMA/LIBRA-phase2

Author: R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, R. Cerulli, C. J. Dai, A. d'Angelo, A. Di Marco, H. L. He, A. Incicchitti, X. H. Ma, V. Merlo, F. Montecchia, X. D. Sheng, and Z. P. Ye
Subjects: dark matter, elementary particle processes, scintillation detectors., Atomic physics. Constitution and properties of matter, QC170-197
Abstract: Several of the many proposed Dark Matter candidate particles, already investigated with lower exposure and a higher software energy threshold, are further analyzed including the first DAMA/LIBRA-phase2 data release, with an exposure of 1.13 tyr and a lower software energy threshold (1 keV). The cumulative exposure above 2 keV considering also DAMA/NaI and DAMA/LIBRA-phase1 results is now 2.46 tyr. The analysis permits to constrain the parameters’ space of the considered candidates restricting their values – with respect to previous analyses – thanks to the increase of the exposure and to the lower energy threshold.
Published: 2019
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7. First model independent results from DAMA/LIBRA-phase2

Author: R. Bernabei, P. Belli, A. Bussolotti, F. Cappella, V. Caracciolo, R. Cerulli, C. J. Dai, A. d’Angelo, A. Di Marco, H. L. He, A. Incicchitti, X. H. Ma, A. Mattei, V. Merlo, F. Montecchia, X. D. Sheng, and Z. P. Ye
Subjects: scintillation detectors, elementary particle processes, Atomic physics. Constitution and properties of matter, QC170-197
Abstract: The first model independent results obtained by the DAMA/LIBRA-phase2 experiment are presented. The data have been collected over 6 annual cycles corresponding to a total exposure of 1.13 t  yr, deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. The DAMA/LIBRA-phase2 apparatus, ≃ 250 kg highly radio-pure NaI(Tl), profits from a second generation high quantum efficiency photomultipliers and of new electronics with respect to DAMA/LIBRA-phase1. The improved experimental configuration has also allowed to lower the software energy threshold. New data analysis strategies are presented. The DAMA/LIBRA-phase2 data confirm the evidence of a signal that meets all the requirements of the model independent Dark Matter (DM) annual modulation signature, at 9.5  C.L. in the energy region (1 - 6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA-phase1 (exposure 1.33 t  yr, collected over 14 annual cycles), the achieved C.L. for the full exposure (2.46 t  yr) is 12.9 ; the modulation amplitude of the single-hit scintillation events is: (0.0103 ± ± 0.0008) cpd/kg/keV, the measured phase is (145 ± 5) d and the measured period is (0.999 ± 0.001) yr, all these values are well in agreement with those expected for DM particles. No systematics or side reaction able to mimic the exploited DM signature (i.e. to account for the whole measured modulation amplitude and to simultaneously satisfy all the requirements of the signature), has been found or suggested by anyone throughout some decades thus far.
Published: 2018
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8. Influence of La–Mn substitutions on magnetic properties of M-type strontium hexaferrites

Author: Z. F. Zi, X. H. Ma, Y. Y. Wei, Q. C. Liu, M. Zhang, X. B. Zhu, and Y. P. Sun
Subjects: Physics, QC1-999
Abstract: M-type strontium hexaferrites of Sr1−xLaxFe12−xMnxO19 (0.0≤x≤0.4) were synthesized by the chemical coprecipitation method. X-ray diffraction (XRD) studies indicate that the samples are single-phase with the space group of P63/mmc. The results of field-emission scanning electronic microscopy (FE-SEM) show that the grains are regular hexagonal platelets with sizes from 0.7 to 1.4 μm. It is observed that the value of Hc increases at low substitution (x ≤ 0.1), reaches a maximum at x = 0.1 and then decreases at x ≥ 0.1, while the value of Ms decreases monotonously with increasing x. The variations of magnetic properties can be tentatively attributed to the effects of La–Mn substitutions. The results above indicate that our samples might be promising candidates for permanent magnets in the future.
Published: 2018
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9. Line-of-shower trigger method to lower energy threshold for GRB detection using LHAASO-WCDA

Author: C. F. Feng, Bin Zhou, X. L. Ji, R. Lu, H. B. Xiao, J. R. Shi, W. Zeng, Z. H. Wang, Shengxue Zhang, Pak-Hin Thomas Tam, H. C. Li, Jun Liu, H. Y. Jia, B. D'Ettorre Piazzoli, W. X. Wu, Junjie Mao, Y. Q. Guo, Dong Liu, F. Ji, H. R. Wu, Y. J. Wei, Alejandro Sáiz, Oleg Shchegolev, L. Feng, V. Rulev, L. Xue, Xuliang Chen, Xing-Yuan Hou, D. M. Wei, S. Hu, M. L. Chen, Jianeng Zhou, J. Y. Liu, Warit Mitthumsiri, Y. Zhang, Q. An, Y. He, Q. Gao, Ruizhi Yang, X. N. Sun, H. B. Hu, H. Liu, L. Chen, X. G. Wang, S. Q. Xi, J. Fang, X. H. You, Ping Zhou, Z. C. Huang, Y. Z. Li, P. F. Zhang, C. Y. Wu, Hong-Guang Wang, G. M. Xiang, W. Liu, Yu-Lei Chen, Zihuang Cao, X. C. Chang, Z. K. Zeng, Y. J. Bi, H. D. Liu, Y. D. Cheng, Bo Zhang, Y. Zheng, L. Q. Yin, Duo Yan, F. Zheng, Hao Zhou, X. X. Zhou, Q. Yuan, Hefan Li, J. F. Chang, Z. X. Liu, Felix Aharonian, H. N. He, C. D. Gao, Lei Zhao, Q. H. Chen, Youping Li, Y. M. Ye, B. B. Li, Yongchun Wang, Y. D. Cui, Bai Yibing, L. P. Wang, J. B. Zhao, Y. J. Wang, J. Y. Yang, S. Z. Chen, Yunchao Liu, B. Z. Dai, Rong Xu, Z. X. Fan, Z. Y. You, Z. G. Dai, X. F. Wu, He Zhang, S. H. Feng, S. B. Yang, J. J. Xia, W. Gao, S. L. He, Y. P. Wang, B. M. Chen, Fan Yang, A. Masood, Kun Fang, S.H. Chen, Yugang Zhang, H. Cai, Lang Shao, H. Wang, J.W. Xia, L. Z. Zhao, G. C. Xiao, X. X. Zhai, Y. C. Nan, Shi-Qi Hu, X. J. Bi, Z. Li, R. Liu, E. W. Liang, X. Zuo, M. J. Yang, Y. H. Yao, W. L. Li, L. X. Zhang, H. K. Lv, Xufang Li, B. Y. Pang, Zebo Tang, M. H. Gu, Z. Y. Pei, Xuejiao Li, F. R. Zhu, T. L. Chen, Qie Sun, K. J. Zhu, Ying Zhang, H. M. Zhang, J. Chen, H. L. Dai, Y. L. Xin, T. Wen, S. W. Cui, M. Zha, J. C. He, W. H. Huang, L. X. Bai, Binyu Zhao, Yun-Feng Liang, Jixia Li, X. H. Cui, Xinbo He, K. Jiang, X. J. Hu, J. W. Zhang, Li-Sheng Geng, Wenwu Tian, Z. X. Wang, Xiaofei Zhang, David Ruffolo, Yu. V. Stenkin, C. Hou, Z. B. Sun, Shuibin Lin, Lu Zhang, K. Levochkin, Cheng Guang Zhu, X. D. Sheng, Minghao Qi, Houdun Zeng, Jun-Jie Wei, Jia Zhang, Y. A. Han, H. B. Li, Danzengluobu, Rui Zhang, H. C. Song, Linbin Yang, Y. Z. Fan, J. T. Cai, H. H. He, Y. M. Xing, F. Y. Li, D. H. Huang, H. Zhu, Xiang Zhang, M. M. Ge, J. G. Guo, S. R. Zhang, N. Cheng, L. L. Ma, G. H. Gong, J. S. Wang, Cunguo Wang, Shujuan Liu, N. Yin, Y. H. Yu, W. J. Long, Axikegu, Xuelong Wang, P. P. Zhang, Chunlong Li, Minghui Liu, D. Bastieri, Jinyao Liu, Z. G. Yao, X. H. Ma, M. Heller, K. Li, Z. J. Jiang, J. Liu, R. N. Wang, V. I. Stepanov, Jian Wang, Chiming Jin, D.A. Kuleshov, G. G. Xin, M. J. Chen, S. P. Zhao, Y. Y. Guo, Donglian Xu, X. L. Guo, X. J. Dong, Y. K. Hor, T. Montaruli, Y. L. Feng, W. Wang, P. Pattarakijwanich, S. Wu, B. D. Wang, C. X. Liu, Y. W. Bao, X. T. Huang, R. Zhou, L. Y. Wang, D. della Volpe, C. W. Yang, Jun-Hui Fan, Zujian Wang, Q. B. Gou, Qizhi Huang, B. Liu, Bingshui Gao, Xiang-Yu Wang, Tao Zeng, and Bin Ma
Subjects: Physics, Nuclear and High Energy Physics, Cherenkov detector, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics, law.invention, Air shower, Nuclear Energy and Engineering, Duty cycle, law, Observatory, Gamma-ray burst, Energy (signal processing), Line (formation)
Abstract: Observation of high energy and very high emission from Gamma Ray Bursts (GRBs) is crucial to study the gigantic explosion and the underline processes. With a large field-of-view and almost full duty cycle, the Water Cherenkov Detector Array (WCDA), a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), is appropriate to monitor the very high energy emission from unpredictable transients such as GRBs. Nevertheless, the main issue for an extensive air shower array is the high energy threshold which limits the horizon of the detector. To address this issue a new trigger method is developed in this article to lower the energy threshold of WCDA for GRB observation. The proposed method significantly improves the detection efficiency of WCDA for gamma-rays around the GRB direction at 10-300 GeV. The sensitivity of the WCDA for GRB detection with the new trigger method is estimated. The achieved sensitivity of the quarter WCDA array above 10 GeV is comparable with that of Fermi-LAT. The data analysis process and corresponding fluence upper limit for GRB 190719C is presented as an example.
Published: 2021
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10. Constraints on heavy decaying dark matter from 570 days of LHAASO observations

Author: Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, E S, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, Y, Chen, H L, Cheng, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B, D'Ettorre Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, X T, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, W K, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, Q, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, W H, Huang, X T, Huang, X Y, Huang, Y, Huang, Z C, Huang, X L, Ji, H Y, Jia, K, Jia, K, Jiang, Z J, Jiang, M, Jin, M M, Kang, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, W J, Long, R, Lu, Q, Luo, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, Y C, Nan, Z W, Ou, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, A, Sáiz, C Y, Shao, L, Shao, O, Shchegolev, X D, Sheng, J Y, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R, Wang, R N, Wang, W, Wang, X G, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, X F, Wu, Y S, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, G G, Xin, Y L, Xin, Y, Xing, Z, Xiong, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, H W, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H, Yue, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, F, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S B, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, S, Ando, M, Chianese, D F G, Fiorillo, G, Miele, K C Y, Ng, and GRAPPA (ITFA, IoP, FNWI)
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics (astro-ph.CO), High Energy Physics - Phenomenology (hep-ph), General Physics and Astronomy, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.
Published: 2022

11. A dynamic range extension system for LHAASO WCDA-1

Author: F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, null Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo
Subjects: Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Dynamic range, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Extension (predicate logic), Measure (mathematics), Effective nuclear charge, Nuclear physics, Air shower, Nuclear Energy and Engineering, Orders of magnitude (time), Energy (signal processing)
Abstract: The main scientific goal of LHAASO-WCDA is to survey gamma-ray sources with energy from 100 GeV to 30 TeV. To observe high-energy shower events, especially to measure the energy spectrum of cosmic rays from 100 TeV to 10 PeV, a dynamic range extension system (WCDA++) is designed to use a 1.5-inch PMT with a dynamic range of four orders of magnitude for each cell in WCDA-1. The dynamic range is extended by using these PMTs to measure the effective charge density in the core region of air shower events, which is an important parameter for identifying the composition of primary particles. The system has been running for more than one year. In this paper, the details of the design and performance of WCDA++ are presented.
Published: 2021
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12. The Change of Solidification Parameters on Hypoeutectic Aluminum–Silicon Alloy Under Different Cooling Rates

Author: X. H. Ma and N. A. Abd Razak
Published: 2022
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13. Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

Author: Alejandro Sáiz, Y. H. Yao, W. X. Wu, P. P. Zhang, Zhuo Li, R. Liu, Pak-Hin Thomas Tam, H. C. Li, Liang Chen, J. C. Wang, Y. L. Xin, L. Chen, M. J. Chen, Hong-Guang Wang, Y. J. Wei, S. Hu, Junjie Mao, Y. Q. Guo, J. Y. Liu, V. Rulev, P. F. Zhang, L. Xue, H. B. Hu, H. Liu, Rui Zhang, Linbin Yang, C. F. Feng, F. Ji, Xiaofei Zhang, F. Zheng, V. I. Stepanov, Ping Zhou, Q. H. Chen, H. R. Wu, Warit Mitthumsiri, X. C. Chang, Z. K. Zeng, C. D. Gao, Bin Zhou, W. L. Li, S. Z. Chen, M. M. Ge, Lei Zhao, Y. Z. Li, Y. Y. Guo, Y. J. Bi, Zhe Cao, Y. K. Hor, Xuejiao Li, H. D. Liu, S. H. Feng, B. Liu, Y. D. Cheng, Bo Zhang, H. K. Lv, H. M. Zhang, K. Levochkin, Y. J. Wang, L. X. Bai, Jixia Li, T. Montaruli, Duo Yan, Hefan Li, Ying Zhang, Bingshui Gao, Q. An, H. B. Xiao, J. R. Shi, X. D. Sheng, Z. X. Liu, W. H. Huang, M. L. Chen, Jianeng Zhou, Q. Gao, Minghao Qi, W. Zeng, Li-Sheng Geng, J. Chen, B. M. Chen, T. Wen, S. W. Cui, Z. X. Wang, Chiming Jin, S. B. Yang, L. Z. Zhao, C. W. Yang, J. B. Zhao, D.A. Kuleshov, Y. M. Xing, L. P. Wang, E. W. Liang, X. F. Wu, Zhe Li, B. Y. Pang, B. B. Li, X. Zuo, Cong Li, S. Q. Xi, Kun Fang, W. Gao, B. Z. Dai, Z. H. Wang, H. Cai, Jun Liu, Zhen Wang, J. C. He, Houdun Zeng, J. Fang, G. C. Xiao, Y. C. Nan, Z. G. Yao, Z. Y. Pei, Jun-Hui Fan, X. X. Zhou, Q. Yuan, H. B. Li, Shi-Qi Hu, G. G. Xin, J. F. Chang, Xufang Li, Oleg Shchegolev, G. M. Xiang, S. P. Zhao, W. Liu, X. L. Ji, M. J. Yang, H. H. He, R. Lu, Zhengguo Cao, Felix Aharonian, J. W. Zhang, H. C. Song, Yongchun Wang, Yugang Zhang, Wenwu Tian, He Zhang, Bai Yibing, S. L. He, Donglian Xu, Y. L. Feng, Zebo Tang, X. L. Guo, Y. D. Cui, X. J. Dong, Zheng Wang, Jun-Jie Wei, Q. B. Gou, Qizhi Huang, H. N. He, K. J. Zhu, M. Zha, B. D. Wang, Ruizhi Yang, X. N. Sun, Y. P. Wang, Z. C. Huang, H. L. Dai, H. Wang, Xiang Zhang, Xing-Yuan Hou, Yunchao Liu, H. Y. Jia, D. M. Wei, Z. G. Dai, Rong Xu, Fan Yang, A. Masood, F. Y. Li, Xinbo He, Youping Li, X. T. Huang, L. Y. Wang, X. R. Li, J. J. Xia, K. Jiang, Binyu Zhao, X. J. Hu, Yun-Feng Liang, W. Wang, Y. A. Han, J. G. Guo, Yu. V. Stenkin, Lang Shao, J.W. Xia, P. Pattarakijwanich, X. H. You, S.H. Chen, S. R. Zhang, C. Hou, Shuibin Lin, Lu Zhang, L. Feng, Xuelong Wang, S. Wu, X. X. Zhai, Xuliang Chen, C. X. Liu, L. L. Ma, Y. He, Z. X. Fan, Z. Y. You, F. R. Zhu, Y. W. Bao, Qie Sun, Yi Chen, X. G. Wang, Yi Zhang, Xiang-Yu Wang, D. H. Huang, R. Zhou, Hao Zhou, H. Zhu, X. J. Bi, D. della Volpe, Tao Zeng, T. L. Chen, Bin Ma, J. S. Wang, Cunguo Wang, L. X. Zhang, Shujuan Liu, N. Yin, N. Cheng, D. Bastieri, X. H. Cui, Cheng Li, W. J. Long, Shengxue Zhang, Axikegu, Li Zhang, G. H. Gong, Danzengluobu, M. H. Gu, Y. H. Yu, Jie Zhang, Y. Z. Fan, Dong Liu, C. Y. Wu, J. T. Cai, Long Chen, Y. Zheng, L. Q. Yin, Y. M. Ye, J. Y. Yang, B D Ettorre Piazzoli, David Ruffolo, Z. B. Sun, Cheng Guang Zhu, X. H. Ma, M. Heller, K. Li, Z. J. Jiang, J. Liu, Yong Zhang, Minghui Liu, R. N. Wang, and Jinyao Liu
Subjects: Physics, Multidisciplinary, Photon, COSMIC cancer database, Proton, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Electron, Astrophysics, 01 natural sciences, Galaxy, Supernova, Crab Nebula, Pulsar, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons—cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3–6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators. Observations of γ-rays with energies up to 1.4 PeV find that 12 sources in the Galaxy are PeVatrons, one of which is the Crab Nebula.
Published: 2021
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14. Physical origin of the non-physical spin evolution of MAXI J1820 + 070

Author: Cunguo Wang, Shaolin Xiong, B. S. Liu, B. B. Wu, H. Gao, J. Y. Liao, H. M. Zhang, R. C. Ma, Y. S. Wang, Y. F. Zhang, Xue-Feng Lu, C. Cai, Lian Tao, Shuinai Zhang, Tong Li, G. H. Gao, S. M. Jia, Tao Luo, M. Wu, X. Y. Song, Bo Li, Wenxiong Li, J. Jin, Xin-Fu Zhao, He-Yang Liu, S. Xiao, Lei Sun, Junqiang Zhang, J. L. Qu, Y. H. Tan, C. K. Li, Y. Nang, Peng Zhang, R. J. Yang, H. W. Liu, N. Sai, Yuan-Yuan Du, Y. G. Zheng, X. X. Li, Z. Chang, Y. B. Chen, Qiu-Yi Luo, Tian-Xiang Chen, Z. W. Li, F. J. Lu, Qingcui Bu, L. M. Song, S. J. Zheng, XiangYang Wen, X. H. Ma, Da-Wei Han, Ya Fang Huang, H. S. Zhao, Yuan You, Qi-Bin Yi, D. K. Zhou, P. J. Wang, W. S. Wang, Ge Ou, Yi Zhang, C. Z. Liu, Sisi Yang, J. Y. Nie, Xin Ren, Liang Zhang, Cheng-Cheng Guo, Ming-Yu Ge, L. Chen, Wan-Chang Zhang, Xiong Li, Yu-Dong Gu, X. J. Liu, Libin Wang, X. L. Cao, Q. Q. Yin, Y. P. Chen, Y. Wang, X. H. Liang, Fuqin Zhang, S. N. Zhang, Y. P. Xu, B. Y. Wu, Xuelong Li, J. Guan, L. D. Kong, Wei Cui, W. C. Zhang, Jia Huo, Gang Li, Wenhan Jiang, Bin Meng, Y. J. Yang, and G. C. Xiao
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Hardness ratio, Astrophysics::High Energy Astrophysical Phenomena, Spin transition, FOS: Physical sciences, Binary number, Astronomy and Astrophysics, Astrophysics, Black hole, Innermost stable circular orbit, Accretion disc, Space and Planetary Science, Coincident, Spectral analysis, 83C57, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: We report on the Insight-HXMT observations of the new black hole X-ray binary MAXI J1820+070 during its 2018 outburst. Detailed spectral analysis via the continuum fitting method shows an evolution of the inferred spin during its high soft sate. Moreover, the hardness ratio, the non-thermal luminosity and the reflection fraction also undergo an evolution, exactly coincident to the period when the inferred spin transition takes place. The unphysical evolution of the spin is attributed to the evolution of the inner disc, which is caused by the collapse of a hot corona due to condensation mechanism or may be related to the deceleration of a jet-like corona. The studies of the inner disc radius and the relation between the disc luminosity and the inner disc radius suggest that, only at a particular epoch, did the inner edge of the disc reach the innermost stable circular orbit and the spin measurement is reliable. We then constrain the spin of MAXI J1820+070 to be a*=0.2^{+0.2}_{-0.3}. Such a slowly spinning black hole possessing a strong jet suggests that its jet activity is driven mainly by the accretion disc rather than by the black hole spin., Comment: 14 pages, 13 figures, 5 tables, accepted for publication in MNRAS
Published: 2021
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15. Correlation between thermal neutrons and soil moisture measured by ENDA

Author: F. Yang, X.-H. Ma, H.-K. Chen, T.-L. Chen, S.-W. Cui, null Danzengluobu, W. Gao, D. Kuleshov, K. Kurinov, B.-B. Li, M.-Y. Liu, Y. Liu, O. Shchegolev, Y. Stenkin, D.-X. Xiao, L.-Q. Yin, and L.-W. Zhang
Subjects: Instrumentation, Mathematical Physics
Abstract: Hadrons are the “skeleton” of extensive air shower (EAS). They possess favorable information concerning composition and energy of cosmic ray. Thermal neutrons generated by the EAS hadrons in the ground as well as charged particles in EAS front plane can be detected by Electron-Neutron detector (EN-detector). A prototype of EN-Detector Array (ENDA), ENDA-16 was built at Large High Altitude Air Shower Observatory (LHAASO) to test its performance of detection of cosmic ray composition and energy spectrum. It has been proved in former work that there is a decrease of thermal neutrons detected in rainy season. For quantitative evaluation of influence of soil moisture on thermal neutrons, at the center of ENDA-16, five soil moisture meters are installed to record soil moisture. Negative correlation between thermal neutron counting rate and soil moisture is obtained. Moreover, it is demonstrated that a soil depth 0.5 m over the soil moisture sensor is enough for monitoring negative correlation between thermal neutron counting rate and soil moisture. The results provide us a method to correct the experimental data during the rainy season so as to reduce systematic uncertainty of thermal neutron measurement in the ENDA experiment.
Published: 2023
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16. HXMT identification of a non-thermal X-ray burst from SGR J1935+2154 and with FRB 200428

Author: Y. J. Jin, Z. Chang, J. Y. Liao, H. M. Zhang, Y. F. Zhang, X. B. Li, Y. G. Li, Chun-sheng Zhang, Wenhan Jiang, Bo Li, Yu-Xuan Zhu, G. H. Gao, J. Jin, M. Wu, Y. Zhang, Xin-Fu Zhao, Zhi Zhang, Y. H. Tan, Y. X. Zhu, R. C. Shang, C. Cai, B. Lu, Fuqin Zhang, J. K. Deng, S. N. Zhang, W. C. Xue, X. X. Li, Y. G. Zheng, J. F. Zhou, Ming-Yu Ge, X. H. Ma, Wenxiong Li, Tian-Xiang Chen, F. J. Lu, Y. S. Wang, D. K. Zhou, Wei Cui, T. Zhang, Aimei Zhang, Lin Lin, Li-Ming Song, B. S. Liu, Lei Sun, C. Z. Liu, S. J. Zheng, Luhua Jiang, Y. P. Xu, B. B. Wu, X. L. Cao, Tao Luo, XiangYang Wen, Xue-Feng Lu, Bin Meng, S. Xiao, Y. B. Chen, Junqiang Zhang, Tong Li, H. W. Liu, N. Sai, Mao-Shun Li, Yunchao Liu, Sisi Yang, Y. J. Yang, S. M. Jia, Yuan You, L. D. Kong, Songbo Zhang, Cunguo Wang, Qi-Bin Yi, Yu-Dong Gu, Q. Q. Yin, Y. P. Chen, Xuelong Li, J. Guan, X. J. Liu, W. Z. Zhang, Yuan-Yuan Du, Gang Chen, X. H. Liang, G. C. Xiao, R. L. Zhuang, GuoQing Liu, Jia Huo, Y. Nang, Gang Li, Shaolin Xiong, Y. J. Zhang, H. Gao, Qiu-Yi Luo, Z. Zhang, Y. L. Tuo, J. W. Yang, Bing Zhang, B. Y. Wu, Lian Tao, X. Y. Song, H. S. Zhao, G. F. Wang, W. S. Wang, Ge Ou, W. C. Zhang, J. Y. Nie, Yi-Qiao Dong, Cheng-Cheng Guo, C. K. Li, H. Xu, Z. W. Li, Da-Wei Han, Z. L. Zhang, M. X. Fu, Yue Zhang, Ya Fang Huang, J. Z. Wang, L. Chen, Wan-Chang Zhang, Weiguang Cui, Qingcui Bu, Min Gao, and J. L. Qu
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010504 meteorology & atmospheric sciences, X-ray, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Magnetar, 01 natural sciences, Coincidence, Radio spectrum, 0103 physical sciences, Thermal, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Event (particle physics), 0105 earth and related environmental sciences, Delay time
Abstract: Fast radio bursts (FRBs) are short pulses observed in radio band from cosmological distances. One class of models invoke soft gamma-ray repeaters (SGRs), or magnetars, as the sources of FRBs. Some radio pulses have been observed from some magnetars, however, no FRB-like events had been detected in association any magnetar burst, including one giant flare. Recently, a pair of FRB-like bursts (FRB 200428 hereafter) separated by milliseconds (ms) were detected from the general direction of the Galactic magnetar SGR J1935+2154. Here we report the detection of a non-thermal X-ray burst in the 1-250 keV energy band with the Insight-HXMT satellite, which we identify as emitted from SGR J1935+2154. The burst showed two hard peaks with a separation of 34 ms, broadly consistent with that of the two bursts in FRB 200428. The delay time between the double radio and X-ray peaks is about 8.57 s, fully consistent with the dispersion delay of FRB 200428. We thus identify the non-thermal X-ray burst is associated with FRB 200428 whose high energy counterpart is the two hard peaks in X-ray. Our results suggest that the non-thermal X-ray burst and FRB 200428 share the same physical origin in an explosive event from SGR J1935+2154., 24 pages, 9 figures, 6 tables; initial submission to a journal on May 9th, 2020. Significant changes include updated localization and detailed spectral evolution of the X-ray burst, and better determination of the two narrow X-ray peaks corresponding to the two radio pulses. Conclusions are strengthened. Nature Astronomy online on Feb. 18, 2021
Published: 2021
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17. First results from DAMA/LIBRA phase2

Author: R. Bernabei, P. Belli, A. Bussolotti, R. Cerulli, A. Di Marco, V. Merlo, F. Montecchia, F. Cappella, A. d’Angelo, A. Incicchitti, A. Mattei, V. Caracciolo, C. J. Dai, H. L. He, X. H. Ma, X. D. Sheng, and Z. P. Ye
Published: 2022
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18. Study of proton irradiation effects on AlGaN/GaN high electron mobility transistors.

Author: Ling Lv, J. G. Ma, Y. R. Cao, J. C. Zhang, W. Zhang, L. Li, S. R. Xu, X. H. Ma, X. T. Ren, and Yue Hao
Published: 2011
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19. DAMA/LIBRA results and perspectives of the second stage

Author: R. Bernabei, P. Belli, F. Cappella, V.Caracciolo, R. Cerulli, C. J. Dai, A. d`Angelo, A. Di Marco, H. L. He, A. Incicchitti, X. H. Ma, F. Montecchia, X. D. Sheng, R. G. Wang, and Z. P. Ye
Subjects: Dark Matter, annual modulation, NaI(Tl) scintillator, Atomic physics. Constitution and properties of matter, QC170-197
Abstract: The DAMA/LIBRA experiment is mainly dedicated to the investigation on DM particles in the Galactic halo by exploiting the model independent Dark Matter (DM) annual modulation signature. The present DAMA/LIBRA and the former DAMA/NaI (exposed masses: about 250 kg and about 100 kg of highly radiopure NaI(Tl), respectively) experiments have released so far a total exposure of 1.17 t · yr collected over 13 annual cycles; they provide a model independent evidence of the presence of DM particles in the galactic halo at 8.9  C.L. The data of another annual cycle in the same DAMA/LIBRA running conditions are at hand. After the substitution (at fall 2010) of all the photomultipliers (PMTs) with new ones, having higher quantum efficiency, DAMA/LIBRA has entered the phase 2; that substitution has allowed to lower the software energy threshold of the experiment in the present data taking. Future perspectives are mentioned.
Published: 2013

20. Insight-HXMT study of the timing properties of Sco X-1

Author: J. Z. Wang, J. Y. Nie, Y. J. Yang, Xiaobo Li, Weiguang Cui, J. Guan, Qingcui Bu, L. M. Song, Yu-Dong Gu, G. C. Xiao, Luhua Jiang, J. Jin, D. K. Zhou, Y. X. Zhu, X. H. Liang, W. C. Zhang, B. Lu, GuoQing Liu, Ming-Yu Ge, Chun-sheng Zhang, Yi-Qiao Dong, Min Gao, B. B. Wu, Wenhan Jiang, Jia Huo, Y. H. Tan, Cheng-Cheng Guo, J. L. Qu, Gang Li, Y. B. Chen, F. J. Lu, Xin-Fu Zhao, R. C. Shang, J. F. Zhou, Bing Li, XiangYang Wen, Lian Tao, Y. S. Wang, Gang Chen, Wei Cui, B. Y. Wu, Tian-Xiang Chen, T. Zhang, X. Y. Song, X. J. Liu, Tao Luo, Da-Wei Han, Bin Meng, L. Chen, Mao-Shun Li, S. Xiao, Xue-Feng Lu, Tong Li, S. M. Jia, Fuqin Zhang, Z. Zhang, S. N. Zhang, Z. Chang, Yunchao Liu, R. L. Zhuang, Junqiang Zhang, Wan-Chang Zhang, W. S. Wang, Y. Nang, Ge Ou, Yuan-Yuan Du, W. Z. Zhang, Lei Sun, Y. J. Jin, C. Z. Liu, J. K. Deng, L. D. Kong, H. W. Liu, N. Sai, Shaolin Xiong, Cunguo Wang, Y. J. Zhang, X. H. Ma, H. Gao, Sisi Yang, Yupeng Xu, Qiu-Yi Luo, X. F. Li, H. S. Zhao, G. F. Wang, Y. L. Tuo, C. Cai, Wenxiong Li, J. W. Yang, Yu-Xuan Zhu, X. L. Cao, X. X. Li, S. J. Zheng, Yuan You, G. H. Gao, Qi-Bin Yi, M. Wu, Q. Q. Yin, Y. P. Chen, Y. Zhang, Y. G. Li, Aimei Zhang, J. Y. Liao, H. M. Zhang, Y. F. Zhang, Ya Fang Huang, Z. L. Zhang, C. K. Li, Z. W. Li, and M. X. Fu
Subjects: Physics, High energy, 010308 nuclear & particles physics, Phase (waves), Astronomy and Astrophysics, Astrophysics, Horizontal branch, 01 natural sciences, law.invention, Telescope, Root mean square, Space and Planetary Science, law, 0103 physical sciences, Modulation (music), 010303 astronomy & astrophysics, Energy (signal processing), Flare
Abstract: We present a detailed timing study of the brightest persistent X-ray source Sco X-1 using the data collected by the Hard X-ray Modulation Telescope ( I n s i g h t -HXMT) from July 2017 to August 2018. A complete Z-track hardness-intensity diagram (HID) is obtained. The normal branch oscillations (NBOs) at ∼ 6 Hz in the lower part of the normal branch (NB) and the flare branch oscillations (FBOs) at ∼ 16 Hz in the beginning part of the flaring branch (FB) are found in observations with the Low Energy X-ray Telescope (LE) and the Medium Energy X-ray Telescope (ME) of I n s i g h t -HXMT, while the horizontal branch oscillations (HBOs) at ∼ 40 Hz and the kilohertz quasi-periodic oscillations (kHz QPOs) at ∼ 800 Hz are found simultaneously above 20 keV for the first time on the horizontal branch (HB) by the High Energy X-ray Telescope (HE) and ME. We find that for all types of the observed QPOs, the centroid frequencies are independent of energy, while the root mean square (rms) increases with energy; the centroid frequencies of both the HBOs and kHz QPOs increase along the Z-track from the top to the bottom of the HB; and the NBOs show soft phase lags increasing with energy. A continuous QPO transition from the FB to NB in ∼ 200 s are also detected. Our results indicate that the non-thermal emission is the origin of all types of QPOs, the innermost region of the accretion disk is non-thermal in nature, and the corona is nonhomogeneous geometrically.
Published: 2020
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21. Dark matter investigation with DAMA set-ups

Author: R. Bernabei, P. Belli, V. Caracciolo, R. Cerulli, A. Di Marco, V. Merlo, F. Cappella, A. d’Angelo, A. Incicchitti, C. J. Dai, X. H. Ma, X. D. Sheng, F. Montecchia, and Z. P. Ye
Subjects: annual modulation, NaI(tl), Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Settore FIS/04, Astrophysics::Instrumentation and Methods for Astrophysics, Dark Matter, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Nuclear Experiment, Atomic and Molecular Physics, and Optics
Abstract: Experimental observations and theoretical arguments at Galaxy and larger scales suggested that a large fraction of the universe is composed by Dark Matter particles. This motivated the DAMA experimental efforts to investigate the presence of such particles in the galactic halo by exploiting a model-independent signature and very highly radiopure set-ups deep underground. Here, a review of the model-independent positive results, obtained by the DAMA set-ups at the Gran Sasso National Laboratory of the INFN, and some of the implications will be given.
Published: 2022
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22. [Associations between gene polymorphisms of signal transducer and activator of transcription 3 and the susceptibility to hepatitis B virus related liver cirrhosis]

Author: X H, Yan, J L, Wu, R, Yu, X H, Ma, Q F, Li, and R F, Xie
Subjects: Liver Cirrhosis, STAT3 Transcription Factor, Hepatitis B virus, Carcinoma, Hepatocellular, Hepatitis B, Chronic, Genotype, Case-Control Studies, Liver Neoplasms, Humans, Genetic Predisposition to Disease, Polymorphism, Single Nucleotide
Abstract: To investigate the associations between gene polymorphisms of signal transducer and activator of transcription 3 (STAT3) and liver cirrhosis (LC) after hepatitis B virus (HBV) infection. A case-control study was conducted in 243 patients with hepatitis B cirrhosis (HBV-LC, case group) and 486 HBV-infected subjects without LC (non-LC, control group) collected from January 2018 to September 2020 at the Changsha Central Hospital Affiliated to Nanhua University. Three single nucleotide polymorphisms (SNPs) of STAT3 gene, including旨在探讨信号传导与转录激活因子3（signal transducer and activator of transcription 3，STAT3）基因多态性与乙型肝炎病毒（hepatitis B virus，HBV）感染后肝硬化（liver cirrhosis，LC）的相关性。本研究采用病例对照研究方法，以2018年1月至2020年9月在南华大学附属长沙市中心医院就诊的243例乙型肝炎肝硬化患者（HBV-LC，实验组）与486例非肝硬化HBV感染者（non-LC，对照组）为研究对象。通过文献和生物信息数据库选定3个STAT3基因单核苷酸多态性（single nucleotide polymorphisms，SNPs）（
Published: 2022

23. [Correlation study between changes in intestinal microflora structure and immune indexes in newly treated patients with pulmonary tuberculosis]

Author: J H, Xie, R, Yu, G M, Shi, X H, Ma, S F, Xiao, Y H, Yi, T, Zhou, and Y G, Xiang
Subjects: Case-Control Studies, Humans, Correlation of Data, Tuberculosis, Pulmonary, Monocytes, Gastrointestinal Microbiome
Abstract: To explore the correlation between the changes of the intestinal flora of newly treated pulmonary tuberculosis patients and the immune indicators of the body, and to provide a reference for the prevention and treatment of pulmonary tuberculosis. A single-center and case-control study was adopted. From October 2020 to April 2021, 43 patients with newly diagnosed tuberculosis in the Department of Tuberculosis, Affiliated Changsha Central Hospital,University of South China were selected as the control group. 43 cases of newly treated pulmonary tuberculosis (PTB), 43 healthy control (HC) during the same period, collected fresh feces and whole blood of subjects, and used Illumina Hiseq high-throughput sequencing technology to analyze 16S of all microorganisms in feces The V4 region of rRNA was amplified and sequenced, and the structure of the intestinal flora was analyzed by QIIME software. Use flow cytometry to determine the subject's immune indicators (CD3探讨初治肺结核患者肠道菌群改变与机体免疫指标的相关性，为肺结核防治提供参考依据。采取单中心病例对照研究，选取2020年10月至2021年4月于南华大学附属长沙中心医院肺结核科，诊断为初治肺结核的患者43例，同期健康查体的人群43名作为对照组。初治肺结核患者（pulmonary tuberculosis，PTB）43例，同期体检健康者（healthy control，HC）43名，收集受试对象新鲜粪便和全血，采用Illumina Hiseq高通量测序技术对粪便中所有微生物16S rRNA的V4区进行扩增测序，通过QIIME软件分析肠道菌群结构。利用流式细胞术测定受试者免疫指标（CD3
Published: 2021

24. First Wide Field-of-view X-Ray Observations by a Lobster-eye Focusing Telescope in Orbit

Author: C. Zhang, Z. X. Ling, X. J. Sun, S. L. Sun, Y. Liu, Z. D. Li, Y. L. Xue, Y. F. Chen, Y. F. Dai, Z. Q. Jia, H. Y. Liu, X. F. Zhang, Y. H. Zhang, S. N. Zhang, F. S. Chen, Z. W. Cheng, W. Fu, Y. X. Han, H. Li, J. F. Li, Y. Li, P. R. Liu, X. H. Ma, Y. J. Tang, C. B. Wang, R. J. Xie, A. L. Yan, Q. Zhang, B. W. Jiang, G. Jin, L. H. Li, X. B. Qiu, D. T. Su, J. N. Sun, Z. Xu, S. K. Zhang, Z. Zhang, N. Zhang, X. Z. Bi, Z. M. Cai, J. W. He, H. Q. Liu, X. C. Zhu, H. Q. Cheng, C. Z. Cui, D. W. Fan, H. B. Hu, M. H. Huang, C. C. Jin, D. Y. Li, H. W. Pan, W. X. Wang, Y. F. Xu, X. Yang, B. Zhang, M. Zhang, W. D. Zhang, D. H. Zhao, M. Bai, Z. Ji, Y. R. Liu, F. L. Ma, J. Su, J. Z. Tong, Y. S. Wang, Z. J. Zhao, C. Feldman, P. O’Brien, J. P. Osborne, R. Willingale, V. Burwitz, G. Hartner, A. Langmeier, T. Müller, S. Rukdee, T. Schmidt, E. Kuulkers, and W. Yuan
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract: As a novel X-ray focusing technology, lobster eye micro-pore optics (MPO) feature both a wide observing field of view and true imaging capability, promising sky monitoring with significantly improved sensitivity and spatial resolution in soft X-rays. Since first proposed by Angel (1979), the optics have been extensively studied, developed and trialed over the past decades. In this Letter, we report on the first-light results from a flight experiment of the Lobster Eye Imager for Astronomy ($LEIA$), a pathfinder of the wide-field X-ray telescope of the Einstein Probe mission. The piggyback imager, launched in July 2022, has a mostly un-vignetted field of view of $18.6^\circ \times 18.6^\circ $. Its spatial resolution is in the range of 4$-$7 arcmin in FWHM and the focal spot effective area is 2$-$3 cm$^2$, both showing only mild fluctuations across the field of view. We present images of the Galactic center region, Sco X-1 and the diffuse Cygnus Loop nebular taken in snapshot observations over 0.5$-$4 keV. These are truly wide-field X-ray images of celestial bodies observed, for the first time, by a focusing imaging telescope. Initial analyses of the in-flight data show excellent agreement between the observed images and the on-ground calibration and simulations. The instrument and its characterization are briefly described, as well as the flight experiment. The results provide a solid basis for the development of the present and proposed wide-field X-ray missions using lobster eye MPO., Comment: 11 pages, 4 figures. Accepted for publication in Astrophysical Journal Letter
Published: 2022
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25. Search for Gamma-Ray Bursts and Gravitational Wave Electromagnetic Counterparts with High Energy X-ray Telescope of \textit{Insight}-HXMT

Author: Yu-Dong Gu, C. K. Li, C. Cai, J. Y. Zhang, Wenxiong Li, Y. Nang, Z. Chang, Yuan-Yuan Du, Z. W. Li, B. Y. Wu, B. B. Wu, Wenhan Jiang, J. Y. Nie, Jia Huo, B. S. Liu, L. D. Kong, F. J. Lu, Y. B. Chen, X. Q. Ren, Yuyang Zhao, Fuqin Zhang, S. N. Zhang, X. X. Li, XiangYang Wen, Lian Tao, Peng Zhang, Gang Li, S. J. Zheng, Bo Li, D. K. Zhou, X. Y. Song, Y. G. Zheng, Y. S. Wang, Tian-Xiang Chen, X. J. Liu, Wei Zhang, Cunguo Wang, Cheng-Cheng Guo, Libin Wang, Yuan You, Qi-Bin Yi, W. C. Zhang, G. H. Gao, Lei Sun, Ya Fang Huang, Y. H. Tan, Wei Cui, M. Wu, Wei Chen, L. Chen, Yi-Yan Yang, Y. H. Zhang, Ming-Yu Ge, H. W. Liu, N. Sai, J. Y. Liao, X. H. Liang, H. M. Zhang, R. C. Ma, Y. P. Xu, Y. F. Zhang, X. B. Li, Xuelong Li, J. Guan, Qingcui Bu, X J Yang, L. M. Song, Tao Luo, S. Xiao, Da-Wei Han, J. L. Qu, Hongfei Liu, X. L. Cao, Q. Q. Yin, Y. P. Chen, J. Jin, Yu-Xuan Zhu, Xin-Fu Zhao, C. Z. Liu, Sisi Yang, R. J. Yang, Qiu-Yi Luo, Y. L. Tuo, Bin Meng, Z. Zhang, Shaolin Xiong, H. Gao, Y. J. Yang, G. C. Xiao, H. S. Zhao, P. J. Wang, W. S. Wang, Ge Ou, X. H. Ma, Xue-Feng Lu, Shuinai Zhang, Tong Li, and S. M. Jia
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, X-ray telescope, Astrophysics, Light curve, Coincidence, law.invention, Telescope, Space and Planetary Science, law, Sensitivity (control systems), Gamma-ray burst, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope
Abstract: The High Energy X-ray telescope (HE) on-board the Hard X-ray Modulation Telescope (\textit{Insight}-HXMT) can serve as a wide Field of View (FOV) gamma-ray monitor with high time resolution ($\mu$s) and large effective area (up to thousands cm$^2$). We developed a pipeline to search for Gamma-Ray Bursts (GRBs), using the traditional signal-to-noise ratio (SNR) method for blind search and the coherent search method for targeted search. By taking into account the location and spectrum of the burst and the detector response, the targeted coherent search is more powerful to unveil weak and sub-threshold bursts, especially those in temporal coincidence with Gravitational Wave (GW) events. Based on the original method in literature, we further improved the coherent search to filter out false triggers caused by spikes in light curves, which are commonly seen in gamma-ray instruments (e.g. \textit{Fermi}/GBM, \textit{POLAR}). We show that our improved targeted coherent search method could eliminate almost all false triggers caused by spikes. Based on the first two years of \textit{Insight}-HXMT/HE data, our targeted search recovered 40 GRBs, which were detected by either \textit{Swift}/BAT or \textit{Fermi}/GBM but too weak to be found in our blind search. With this coherent search pipeline, the GRB detection sensitivity of \textit{Insight}-HXMT/HE is increased to about 1.5E-08 erg/cm$^2$ (200 keV$-$3 MeV). We also used this targeted coherent method to search \textit{Insight}-HXMT/HE data for electromagnetic (EM) counterparts of LIGO-Virgo GW events (including O2 and O3a runs). However, we did not find any significant burst associated with GW events., Comment: 12 pages, 14 figures, 5 tables; accepted for publication in MNRAS
Published: 2021

26. Discovery of a new $\gamma$-ray source LHAASO J0341+5258 with emission up to 200TeV

Author: Zhengguo Cao, L. Feng, Xufang Li, Zebo Tang, Jun-Jie Wei, C. Y. Wu, Jia Zhang, L. X. Bai, Yi Zhang, H. K. Lv, Jixia Li, L. L. Yang, Z. X. Wang, M. Zha, Y. M. Ye, X. H. Ma, L. P. Wang, X. G. Wang, Donglian Xu, X. L. Guo, Y. A. Han, Binyu Zhao, Yun-Feng Liang, Houdun Zeng, Zhe Li, Y. Su, B. Z. Dai, Z. G. Dai, Jinmei Liu, B. D'Ettorre Piazzoli, Z. G. Yao, Y. Zheng, W. X. Wu, M. L. Chen, Jianeng Zhou, Hefan Li, W. Wang, P. Pattarakijwanich, Rong Xu, J. J. Xia, X. X. Zhai, J. Fang, F. R. Zhu, Qie Sun, Yi Chen, H. B. Li, G. M. Xiang, W. Liu, B. Y. Pang, S. Wu, X. L. Ji, R. Lu, K. Li, Y. J. Bi, H. D. Liu, Y. D. Cheng, Bo Zhang, L. Q. Yin, Hanzhong Zhang, C. X. Liu, D. della Volpe, Y. D. Cui, Kun Fang, Yugang Zhang, E. W. Liang, Ping Zhou, Z. J. Jiang, Y. J. Wei, J. Liu, Yong Zhang, Duo Yan, Yu. V. Stenkin, S. L. He, Y. P. Wang, Z. X. Liu, D. H. Huang, R. N. Wang, S. M. Liu, F. Ji, V. Rulev, Y. Z. Li, H. H. He, H. Zhu, C. Hou, Zheng Wang, B. Q. Ma, Y. C. Nan, L. Xue, Jun Liu, Lu Zhang, H. Y. Jia, D. M. Wei, V. I. Stepanov, E. S. Chen, Sina Chen, K. J. Zhu, Y. Q. Qi, Fulai Guo, J. Y. Shi, Minghui Liu, Yi Liu, J. B. Zhao, H. Wang, X. F. Wu, Zhen Wang, Z. X. Fan, Z. Y. You, Shi-Qi Hu, J. Y. Yang, N. Cheng, Z. K. Zeng, C. D. Gao, X. H. You, Long Gao, H. C. Song, Lei Zhao, D.A. Kuleshov, X. X. Zhou, Q. Yuan, B. M. Chen, Ruizhi Yang, X. N. Sun, Shengxue Zhang, Danzengluobu, J. F. Chang, S. P. Zhao, H. Liu, J.W. Xia, W. Gao, G. C. Xiao, Felix Aharonian, Xinbo He, K. Jiang, Pak-Hin Thomas Tam, H. C. Li, Y. Wang, Y. Z. Fan, Dong Liu, Y. W. Bao, P. F. Zhang, X. J. Bi, H. N. He, T. L. Chen, L. Z. Zhao, X. J. Hu, R. Zhou, Ying Zhang, Oleg Shchegolev, Junjie Mao, Y. Q. Guo, F. Y. Li, K. Levochkin, J. T. Cai, X. D. Sheng, Cong Li, X. Zuo, B. B. Li, Long Chen, Yunchao Liu, H. L. Dai, T. Wen, S. W. Cui, S. Z. Chen, David Ruffolo, Y. M. Xing, H. R. Wu, Liang Chen, Xiang-Kun Dong, S. Hu, J. Y. Liu, X. Y. Huang, P. P. Zhang, X. H. Cui, Minghao Qi, Z. B. Sun, Y. Bai, Z. Y. Pei, Cheng Guang Zhu, Yuan-Hao Wang, Zhuo Li, Warit Mitthumsiri, H. M. Zhang, Q. An, Y. H. Yao, W. H. Huang, H. Zhou, W. J. Long, Binbin Zhou, Li-Sheng Geng, R. Liu, Xiang Zhang, J. G. Guo, J. W. Zhang, S. R. Zhang, Wenwu Tian, L. L. Ma, Q. Gao, C. F. Feng, Jiangang He, J. S. Wang, Cunguo Wang, Y. L. Xin, Z. C. Huang, H. B. Hu, N. Yin, B. Q. Qiao, Xin Li, Cheng Li, Jiajun Qin, M. H. Gu, Boyang Wang, Rui Zhang, H. B. Xiao, W. Zeng, L. X. Zhang, S. H. Feng, M. M. Ge, Axikegu, Yonggang Wang, M. J. Chen, Zhao-Qi Wang, Y. Y. Guo, Li Zhang, G. H. Gong, Zhe Cao, Y. K. Hor, Y. H. Yu, T. Montaruli, Jian Wang, Chiming Jin, Z. Min, Xuelong Wang, G. G. Xin, Kai-Kai Duan, D. Bastieri, Y. L. Feng, T. Ke, S. J. Lin, X. T. Huang, L. Y. Wang, B. Liu, Jingzhi Yan, Bingshui Gao, Xiang-Yu Wang, Yulong Li, Tao Zeng, Xuliang Chen, Y. He, C. W. Yang, Jun-Hui Fan, Q. B. Gou, W. L. Li, D. X. Xiao, Qizhi Huang, J. Chen, Xiao-Hu Zhang, H. Cai, M. J. Yang, S. Q. Xi, Hong-Guang Wang, Alejandro Sáiz, Q. H. Chen, S. B. Yang, Fan Yang, A. Masood, F. Zheng, Lang Shao, and M. Heller
Subjects: Physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Flux, Astronomy and Astrophysics, Astrophysics, Galactic plane, Crab Nebula, Pulsar, Space and Planetary Science, Angular diameter, High Energy Physics::Experiment, Supernova remnant, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: We report the discovery of a new unidentified extended $\gamma$-ray source in the Galactic plane named LHAASO J0341+5258 with a pre-trial significance of 8.2 standard deviations above 25 TeV. The best fit position is R.A.$=55.34^{\circ}\pm0.11^{\circ}$ and Dec$=52.97^{\circ}\pm0.07^{\circ}$. The angular size of LHAASO J0341+5258 is $0.29^\circ \pm 0.06^\circ_{stat} \pm0.02^\circ_{sys}$. The flux above 25 TeV is about $20\%$ of the flux of Crab Nebula. Although a power-law fit of the spectrum from 10 TeV to 200 TeV with the photon index $\alpha=2.98 \pm 0.19_{stat} \pm 0.02_{sys}$ is not excluded, the LHAASO data together with the flux upper limit at 10 GeV set by the Fermi LAT observation, indicate a noticeable steepening of an initially hard power-law spectrum %($\alpha \leq 1.75$) spectrum with a cutoff at $\approx 50$ TeV. We briefly discuss the origin of UHE gamma-rays. The lack of an energetic pulsar and a young SNR inside or in the vicinity of LHAASO J0341+5258 challenge, but do not exclude both the leptonic and hadronic scenarios of gamma-ray production., Comment: Accepted by APJL
Published: 2021

27. Insight-HXMT observation on 4U 1608–52: Evolving spectral properties of a bright type-I X-ray burst

Author: S. N. Zhang, W. C. Jiang, W. S. Wang, Ge Ou, Z. Chang, J. F. Zhou, X.Q. Ren, C. Z. Liu, C. L. Zhang, Tian-Xiang Chen, Min Gao, H. S. Zhao, Sisi Yang, G. F. Wang, D. K. Zhou, Yi Zhang, X. J. Liu, J. L. Qu, G. C. Xiao, Jia Huo, Z. L. Zhang, Y. G. Li, M. X. Fu, Ya Fang Huang, Bing Li, F. Zhang, Chun-sheng Zhang, X. F. Li, Aimei Zhang, W. Z. Zhang, J. Z. Wang, Liang Sun, Y. B. Chen, Xue-Feng Lu, F. J. Lu, S. M. Jia, XiangYang Wen, Lian Tao, Yuan You, Junke Zhang, Gang Li, Y. S. Wang, Wei Zhang, B. Y. Wu, Qi-Bin Yi, B. B. Wu, Mao-Shun Li, Yunchao Liu, Y. J. Yang, Tao Luo, Xiaobo Li, L. D. Kong, S. Xiao, Yi-Qiao Dong, X. L. Cao, W. C. Zhang, Q. Luo, Weiguang Cui, X. X. Li, Yuan-Yuan Du, J. Y. Liao, H. M. Zhang, Gang Chen, Qingcui Bu, B. Lu, Y. H. Tan, J. K. Deng, Cheng-Cheng Guo, H. W. Liu, N. Sai, Q. Q. Yin, Y. P. Chen, Y. F. Zhang, C. K. Li, L. M. Song, Yu-Dong Gu, J. Jin, G. H. Gao, Xin-Fu Zhao, S. J. Zheng, Y. X. Zhu, C. Cai, Z. W. Li, Zhi-Xiang Zhang, X. H. Ma, Ming-Yu Ge, M. Wu, Y. Zhang, C. Wang, Wenxiong Li, Andrea Santangelo, Yu-Xuan Zhu, Shaolin Xiong, Luhua Jiang, Y. P. Xu, Y. J. Zhang, H. Gao, X. H. Liang, J. Guan, Ti-Pei Li, Y. L. Tuo, J. W. Yang, GuoQing Liu, Wei Cui, Long Ji, T. Zhang, L. Chen, J. Y. Nie, Da-Wei Han, Bin Meng, and Y. Nang
Subjects: Physics, Thermonuclear fusion, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Spectral properties, X-ray, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radius, Astrophysics, 01 natural sciences, symbols.namesake, Neutron star, Space and Planetary Science, 0103 physical sciences, Eddington luminosity, Reflection (physics), symbols, Spectral analysis, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The evidences for the influence of thermonuclear (type-I) X-ray bursts upon the surrounding environments in neutron star low-mass X-ray binaries (LMXB) were detected previously via spectral and timing analyses. Benefitting from a broad energy coverage of Insight-HXMT, we analyze one photospheric radius expansion (PRE) burst, and find an emission excess at soft X-rays. Our spectral analysis shows that, such an excess is not likely relevant to the disk reflection induced by the burst emission and can be attributed to an enhanced pre-burst/persistent emission. We find that the burst and enhanced persistent emissions sum up to exceed Eddington luminosity by ∼ 40 percentages. We speculate that the enhanced emission is from a region beyond the PRE radius, or through the Comptonization of the corona.
Published: 2019
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28. The Intense Substorm Incidence in Response to Interplanetary Shock Impacts and Influence on Energetic Electron Fluxes at Geosynchronous Orbit

Author: Q.-G. Zong, Ying Liu, and X.‐H. Ma
Subjects: Physics, Geophysics, Space and Planetary Science, Substorm, Geosynchronous orbit, Electron, Astrophysics, Interplanetary spaceflight, Shock (mechanics)
Published: 2019
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29. The Annual Modulation Signature for Dark Matter: DAMA/LIBRA-Phase1 Results and Perspectives

Author: Rita Bernabei, Pierluigi Belli, Fabio Cappella, Vincenzo Caracciolo, Simone Castellano, Riccardo Cerulli, Chang Jang Dai, Annelisa d’Angelo, Silio d’Angelo, Alessandro Di Marco, H. L. He, Antonella Incicchitti, H. H. Kuang, X. H. Ma, Francesco Montecchia, X. D. Sheng, Rui Guang Wang, and Zi-Piao Ye
Subjects: Physics, QC1-999
Abstract: The results obtained with the total exposure of 1.04 ton × yr collected by DAMA/LIBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles are summarized. The DAMA/LIBRA-phase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton × yr, corresponding to 14 annual cycles) give evidence at 9.3 σ C.L. for the presence of Dark Matter (DM) particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radiopure NaI(Tl) target. The modulation amplitude of the single-hit events in the (2–6) keV energy interval is 0.0112±0.0012 cpd/kg/keV; the measured phase is 144±7 days and the measured period is 0.998±0.002 yr; values are in a good well in agreement with those expected for DM particles. No systematic or side reactions able to mimic the exploited DM signature have been found or suggested by anyone over more than a decade. Some of the perspectives of the presently running DAMA/LIBRA-phase2 are outlined.
Published: 2014
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30. Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Author: Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, H, Cai, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, B M, Chen, E S, Chen, J, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, X L, Chen, Y, Chen, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B D'Ettorre, Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, X J, Dong, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, J C, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, Q L, Huang, W H, Huang, X T, Huang, X Y, Huang, Z C, Huang, F, Ji, X L, Ji, H Y, Jia, K, Jiang, Z J, Jiang, C, Jin, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, Z X, Liu, W J, Long, R, Lu, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, T, Montaruli, Y C, Nan, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, V, Rulev, A, Sáiz, L, Shao, O, Shchegolev, X D, Sheng, J R, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R N, Wang, W, Wang, X G, Wang, X J, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, W X, Wu, X F, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, H B, Xiao, G G, Xin, Y L, Xin, Y, Xing, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, J W, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, and X, Zuo
Subjects: General Physics and Astronomy
Abstract: Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.
Published: 2021

31. [Analysis of risk factors and construction of predictive nomogram for early recurrence after radiofrequency ablation of hepatocellular carcinoma]

Author: R C, Han, X H, Ma, S, Wang, Y, Yang, B, Feng, M, Liang, and X M, Zhao
Subjects: Nomograms, Radiofrequency Ablation, Carcinoma, Hepatocellular, Risk Factors, Liver Neoplasms, Catheter Ablation, Humans, Neoplasm Recurrence, Local, Retrospective Studies
Published: 2021

32. [Comparison of interventional and surgical treatment of paravalvular leak after cardiac valve replacement]

Author: J Z, Pu, W H, Wu, Y T, Ke, L J, Huang, X H, Ma, and C, Zhang
Subjects: Heart Valve Prosthesis Implantation, Cardiac Catheterization, Treatment Outcome, Risk Factors, Heart Valve Prosthesis, Humans, Heart Valves, Aged, Retrospective Studies
Published: 2021

33. [Value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging and diffusion-weighted MR imaging in predicting microvascular invasion in hepatocellular carcinoma and the prognostic significance]

Author: Y J, Zhu, B, Feng, B Z, Wang, S, Wang, F, Ye, X H, Ma, and X M, Zhao
Subjects: Gadolinium DTPA, Carcinoma, Hepatocellular, Diffusion Magnetic Resonance Imaging, Liver Neoplasms, Contrast Media, Humans, Gadolinium, Prognosis, Magnetic Resonance Imaging, Retrospective Studies
Published: 2021

34. Energetic Electron Enhancement and Dropout Echoes Induced by Solar Wind Dynamic Pressure Decrease: The Effect of Phase Space Density Profile

Author: Yixin Hao, Q.-G. Zong, Y. Liu, Chao Yue, and X.‐H. Ma
Subjects: Physics, Solar wind, Geophysics, Space and Planetary Science, Phase space, Dropout (communications), Dynamic pressure, Electron, Computational physics
Published: 2021
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35. QPOs and Orbital elements of X-ray binary 4U 0115+63 during the 2017 outburst observed by Insight-HXMT

Author: Q Lou, Yuan You, Qi-Bin Yi, X. X. Li, S. J. Zheng, Cunguo Wang, J. Jin, H M Zhang, Xin-Fu Zhao, H. S. Zhao, Lei Sun, Wenhan Jiang, G. H. Gao, He-Yang Liu, Y. J. Yang, Xiong Li, Yu-Dong Gu, B. S. Liu, X. H. Ma, Y. P. Xu, Yi Zhang, Y. H. Tan, H. W. Liu, Y Z Ding, N. Sai, M. Wu, G. C. Xiao, W. C. Zhang, Yuan-Yuan Du, Y. G. Zheng, Y. Nang, C. Cai, L. Chen, C. Z. Liu, P. J. Wang, F. J. Lu, J. L. Qu, Bin Meng, Xue-Feng Lu, XiangYang Wen, L. D. Kong, Xuelong Li, J. Guan, S. M. Jia, Wenxiong Li, P Zhang, Fuqin Zhang, S. N. Zhang, Tian-Xiang Chen, Sisi Yang, X. L. Cao, C. K. Li, Y. B. Chen, D. K. Zhou, Y. S. Wang, Libin Wang, J. Y. Liao, Q. Q. Yin, Y. P. Chen, Lian Tao, Ti-Pei Li, R. C. Ma, Y. F. Zhang, Qingcui Bu, Bo Li, B. B. Wu, X. Y. Song, Shuang-Nan Zhang, Junqiang Zhang, W. S. Wang, L. M. Song, Wei Cui, Z. W. Li, Ming-Yu Ge, Wei Wang, Tao Luo, S. Xiao, Xin Ren, Ya Fang Huang, X. J. Liu, Jia Huo, C Zhi, Gang Li, B. Y. Wu, Shaolin Xiong, H. Gao, X. H. Liang, Y. L. Tuo, R. J. Yang, Wei Zhang, Cheng-Cheng Guo, Da-Wei Han, and J. Y. Nie
Subjects: Physics, Orbital elements, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Light curve, 01 natural sciences, Spectral line, Luminosity, Neutron star, Wavelet, Space and Planetary Science, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Energy (signal processing)
Abstract: In this paper, we presented a detailed timing analysis of a prominent outburst of 4U 0115+63 detected by \textit{Insight}-HXMT in 2017 August. The spin period of the neutron star was determined to be $3.61398\pm 0.00002$ s at MJD 57978. We measured the period variability and extract the orbital elements of the binary system. The angle of periastron evolved with a rate of $0.048\pm0.003$ $yr^{-1}$. The light curves are folded to sketch the pulse profiles in different energy ranges. A multi-peak structure in 1-10 keV is clearly illustrated. We introduced wavelet analysis into our data analysis procedures to study QPO signals and perform a detailed wavelet analysis in many different energy ranges. Through the wavelet spectra, we report the discovery of a QPO at the frequency $\sim 10$ mHz. In addition, the X-ray light curves showed multiple QPOs in the period of $\sim 16-32 $ s and $\sim 67- 200 $ s. We found that the $\sim100$ s QPO was significant in most of the observations and energies. There exist positive relations between X-ray luminosity and their Q-factors and S-factors, while the QPO periods have no correlation with X-ray luminosity. In wavelet phase maps, we found that the pulse phase of $\sim 67- 200 $ s QPO drifting frequently while the $\sim 16-32 $ s QPO scarcely drifting. The dissipation of oscillations from high energy to low energy was also observed. These features of QPOs in 4U 0115+63 provide new challenge to our understanding of their physical origins., 14 pages, 9 figures, and 6 tables. This work has been submitted to MNRAS after the referee's report
Published: 2021

36. Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

Author: F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, H, Cai, J T, Cai, Z, Cao, J, Chang, J F, Chang, X C, Chang, B M, Chen, J, Chen, L, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, X L, Chen, Y, Chen, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, B, D'Ettorre Piazzoli, X J, Dong, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, Y L, Feng, B, Gao, C D, Gao, Q, Gao, W, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, J C, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, Q L, Huang, W H, Huang, X T, Huang, Z C, Huang, F, Ji, X L, Ji, H Y, Jia, K, Jiang, Z J, Jiang, C, Jin, D, Kuleshov, K, Levochkin, B B, Li, C, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, K, Li, W L, Li, X, Li, X R, Li, Y, Li, Y Z, Li, Z, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y N, Liu, Z X, Liu, W J, Long, R, Lu, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, W, Mitthumsiri, T, Montaruli, Y C, Nan, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, D, Ruffolo, V, Rulev, A, Sáiz, L, Shao, O, Shchegolev, X D, Sheng, J R, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R N, Wang, W, Wang, X G, Wang, X J, Wang, X Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z, Wang, Z H, Wang, Z X, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, W X, Wu, X F, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, G, Xiao, H B, Xiao, G G, Xin, Y L, Xin, Y, Xing, D L, Xu, R X, Xu, L, Xue, D H, Yan, C W, Yang, F F, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, J W, Zhang, L, Zhang, L X, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y, Zhang, Y F, Zhang, Y L, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, and X Y, Huang
Abstract: We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.
Published: 2021

37. Three Pulsars Discovered by FAST in the Globular Cluster NGC 6517 with a Pulsar Candidate Sifting Code Based on Dispersion Measure to Signal-to-Noise Ratio Plots

Author: Scott M. Ransom, Lin Wang, Peng Jiang, Duncan R. Lorimer, Lei Qian, X. H. Ma, Zhen Yan, Jin-Tao Luo, and Zhichen Pan
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, media_common.quotation_subject, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Radio telescope, Pulsar, Space and Planetary Science, Position (vector), Sky, Globular cluster, 0103 physical sciences, Dispersion (optics), Cluster (physics), Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Spin-½, media_common
Abstract: We report the discovery of three new pulsars in the Globular Cluster (GC) NGC6517, namely NGC 6517 E, F, and G, made with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The spin periods of NGC 6517 E, F, and G are 7.60~ms, 24.89~ms, and 51.59~ms, respectively. Their dispersion measures are 183.29, 183.713, and 185.3~pc~cm$^{-3}$, respectively, all slightly larger than those of the previously known pulsars in this cluster. The spin period derivatives are at the level of 1$\times$10$^{-18}$~s~s$^{-1}$, which suggests these are recycled pulsars. In addition to the discovery of these three new pulsars, we updated the timing solutions of the known isolated pulsars, NGC 6517 A, C, and D. The solutions are consistent with those from Lynch et al. (2011) and with smaller timing residuals. From the timing solution, NGC 6517 A, B (position from Lynch et al. 2011), C, E, and F are very close to each other on the sky and only a few arcseconds from the optical core of NGC 6517. With currently published and unpublished discoveries, NGC6517 now has 9 pulsars, ranking 5$^{th}$ of the GCs with the most pulsars. The discoveries take advantage of the high sensitivity of FAST and a new algorithm used to check and filter possible candidate signals., Comment: 10 pages, 3 figure, 2 tables, accepted by RAA, comments are always welcomed!
Published: 2021
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38. Discovery of the Ultra-high energy gamma-ray source LHAASO J2108+5157

Author: Zhen Cao, F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Zhe Cao, J. Chang, J. F. Chang, B. M. Chen, E. S. Chen, J. Chen, Liang Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. D’Ettorre Piazzoli, B. Z. Dai, H. L. Dai, Z. G. Dai, Dan-Zeng Dan-Zeng-Luo-Bu, D. della Volpe, X. J. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, X. Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, T. Ke, D. Kuleshov, K. Levochkin, B. B. Li, Cheng Li, Cong Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, Z. Min, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. Y. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, J. Z. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. X. Zhang, Li Zhang, Lu Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Y. L. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Molecular cloud, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Flux, Sigma, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Gamma-ray astronomy, Space and Planetary Science, Energy spectrum, Ultrahigh energy, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the discovery of a UHE gamma-ray source, LHAASO J2108+5157, by analyzing the LHAASO-KM2A data of 308.33 live days. Significant excess of gamma-ray induced showers is observed in both energy bands of 25-100 TeV and $\gt$100 TeV with 9.5 sigma and 8.5 sigma, respectively. This source is not significantly favored as an extensive source with the angular extension smaller than the point-spread function of KM2A. The measured energy spectrum from 20 to 200 TeV can be approximately described by a power-law function with an index of -2.83$\pm$ 0.18stat. A harder spectrum is demanded at lower energies considering the flux upper limit set by Fermi-LAT observations. The position of the gamma-ray emission is correlated with a giant molecular cloud, which favors a hadronic origin. No obvious counterparts have been found, deeper multiwavelength observations will help to shed new light on this intriguing UHE source., Comment: 12 pages, 7 figures, accepted by ApJL
Published: 2021
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39. DAMA RESULTS: DARK MATTER IN THE GALACTIC HALO

Author: R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, R. Cerulli, C. J. Dai, A. d’Angelo, A. Di Marco, H. L. He, A. Incicchitti, X. H. Ma, F. Montecchia, X. D. Sheng, R. G. Wang, and Z. P. Ye
Subjects: Engineering (General). Civil engineering (General), TA1-2040
Abstract: Experimental efforts and theoretical developmens support that most of the Universe is Dark and a large fraction of it should be made of relic particles; many possibilities are open on their nature and interaction types. In particular, the DAMA/LIBRA experiment at Gran Sasso Laboratory (sensitive mass: ~250 kg) is mainly devoted to the investigation of Dark Matter (DM) particles in the Galactic halo by exploiting the model independent DM annual modulation signature with higly radiopure Na I(Tl) targets. DAMA/LIBRA is the succesor of the first generation DAMA/NaI (sensitive mass: ~100 kg); cumulatively the two experiments have released so far the results obtained by analyzing an exposure of 1.17 t yr, collected over 13 annual cycles. The data show a model independent evidence of the presence of DM particles in the galactic halo at 8.9σ confidence level (C.L.). Some of the already achieved results are shortly reminded, the last upgrade occurred at fall 2010 is mentioned and future perspectives are sumarized.
Published: 2013
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40. Insight-HXMT observations of Swift J0243.6+6124: the evolution of RMS pulse fractions at super-Eddington luminosity

Author: Da-Wei Han, Luhua Jiang, Y. P. Xu, C. Cai, X. F. Li, Zhi Zhang, Mao-Shun Li, M. X. Fu, C. K. Li, Wenxiong Li, B. S. Liu, Wenhan Jiang, J. Z. Wang, X. H. Liang, Bing Li, Tao Luo, Y. B. Chen, B. Y. Wu, Weiguang Cui, S. Xiao, Qingcui Bu, Y. S. Wang, Z. W. Li, Chun-sheng Zhang, Yuan-Yuan Du, Xiaobo Li, X. L. Cao, J. Y. Nie, Y. X. Zhu, Ming-Yu Ge, Y. G. Zheng, Yi Jung Yang, J. Y. Liao, Min Gao, H. M. Zhang, Fuqin Zhang, S. N. Zhang, Y. Nang, Y. J. Jin, J. K. Deng, J. Guan, Wei Zhang, Z. Chang, Tian-Xiang Chen, Yi-Qiao Dong, Q. Q. Yin, Y. P. Chen, Cheng-Cheng Guo, Yunchao Liu, J. L. Qu, F. J. Lu, Long Ji, X. H. Ma, GuoQing Liu, Yan Ji Yang, Jia Huo, Gang Chen, W. C. Zhang, Y. F. Zhang, B. Lu, XiangYang Wen, B. B. Wu, Junqiang Zhang, Li-Ming Song, G Ou, Z. L. Zhang, Gang Li, Lian Tao, Y. H. Tan, D. K. Zhou, Xue-Feng Lu, Zhao Zhang, X. Y. Song, Ya Fang Huang, Tong Li, Lei Sun, L. Chen, Yuan You, J. F. Zhou, S. M. Jia, Yu-Xuan Zhu, Ling-Jun Wang, W. Z. Zhang, Qi-Bin Yi, Cunguo Wang, Wei Cui, T. Zhang, L. D. Kong, X. J. Liu, H. W. Liu, X. X. Li, Yu-Dong Gu, N. Sai, S. J. Zheng, Y. G. Li, Aimei Zhang, G. H. Gao, M. Wu, Y. Zhang, R. L. Zhuang, J. Jin, Xin-Fu Zhao, R. C. Shang, C. Z. Liu, Sisi Yang, Shaolin Xiong, Y. J. Zhang, H. Gao, Y. L. Tuo, J. W. Yang, Qiu-Yi Luo, G. C. Xiao, H. S. Zhao, Bin Meng, P. J. Wang, G. F. Wang, and W. S. Wang
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Swift, Physics, Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Relative strength, Astrophysics::Cosmology and Extragalactic Astrophysics, Pulse (physics), Luminosity, symbols.namesake, Radiation pressure, Space and Planetary Science, Eddington luminosity, symbols, Astrophysics::Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, computer, Energy (signal processing), Astrophysics::Galaxy Astrophysics, computer.programming_language
Abstract: Based on Insight-HXMT data, we report on the pulse fraction evolution during the 2017–2018 outburst of the newly discovered first Galactic ultraluminous X-ray (ULX) source Swift J0243.6+6124. The pulse fractions of 19 observation pairs selected in the rising and fading phases with similar luminosity are investigated. The results show a general trend of the pulse fraction increasing with luminosity and energy at supercritical luminosity. However, the relative strength of the pulsation between each pair evolves strongly with luminosity. The pulse fraction in the rising phase is larger at luminosity below 7.71 × 1038 erg s−1, but smaller at above. A transition luminosity is found to be energy independent. Such a phenomenon is first confirmed by Insight-HXMT observations and we speculate that it may have relation with the radiation-pressure-dominated accretion disc.
Published: 2020

41. [The mid-term and long-term results of endovascular treatment of C/D aorto-iliac artery occlusive disease]

Author: X, Jia, W, Guo, X P, Liu, J, Xiong, X H, Ma, H P, Zhang, and Y L, Xu
Subjects: Treatment Outcome, Endovascular Procedures, Humans, Arterial Occlusive Diseases, Stents, Prosthesis Design, Iliac Artery, Vascular Patency, Retrospective Studies
Published: 2020

42. Switches between accretion structures during flares in 4U 1901+03

Author: Z. Chang, Fuqin Zhang, S. N. Zhang, Qiu-Yi Luo, Y. B. Chen, B. B. Wu, Tao Luo, Aimei Zhang, J. Y. Zhang, Ming-Yu Ge, Armin Nabizadeh, Y. G. Li, S. Xiao, Y. L. Tuo, J. W. Yang, L. Chen, Chun-sheng Zhang, Peng Zhang, Yu-Dong Gu, Sergey S. Tsygankov, C. K. Li, Y. J. Jin, J. Y. Nie, M. X. Fu, Yue Zhang, X. J. Liu, Luhua Jiang, Y. P. Xu, Zhao Zhang, G. C. Xiao, Bo Li, H. Xu, Yu-Xuan Zhu, J. Z. Wang, X. H. Liang, W. Z. Zhang, L. Sun, Z. W. Li, G. H. Gao, Yanji Yang, Wan-Chang Zhang, Weiguang Cui, C. Cai, F. J. Lu, Yunchao Liu, Qingcui Bu, X. L. Cao, B. S. Liu, Bin Meng, D. K. Zhou, Y. J. Yang, Shaolin Xiong, Wenxiong Li, Tian-Xiang Chen, Lian Tao, Yi Zhang, Y. J. Zhang, M. Wu, Andrea Santangelo, XiangYang Wen, Suleimanov, H. Gao, Z. Zhang, L. D. Kong, X. Y. Song, Long Ji, W. C. Zhang, Q. B. Yi, B. Y. Wu, Mao-Shun Li, Q. Q. Yin, You-Hong Zhang, H. W. Liu, N. Sai, Da-Wei Han, J. Y. Liao, H. M. Zhang, Zhi Zhang, Ya Fang Huang, Y. F. Zhang, Min Gao, X. B. Li, B. Lu, J. L. Qu, Yi-Qiao Dong, Wenhan Jiang, Cheng-Cheng Guo, Y. S. Wang, Doroshenko, Yuan-Yuan Du, C. Z. Liu, Y X Zhu, Y. P. Chen, Sisi Yang, Y. H. Tan, J. F. Zhou, J. Jin, Xin-Fu Zhao, R. C. Shang, Xuelong Li, J. Guan, GuoQing Liu, Jia Huo, Gang Li, Lorenzo Ducci, Wei Cui, T. Zhang, Li-Ming Song, Xue-Feng Lu, Shuinai Zhang, S. M. Jia, He-Yang Liu, Y. Nang, R. L. Zhuang, J. K. Deng, C. Wang, X. H. Ma, H. S. Zhao, Ti-Pei Li, P. J. Wang, G. F. Wang, W. S. Wang, Ge Ou, Gang Chen, Yuan You, X. X. Li, and S. J. Zheng
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Accretion (astrophysics), Spectral line, Beam pattern, Neutron star, Accretion rate, Pulsar, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Polar cap, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We report on our analysis of the 2019 outburst of the X-ray accreting pulsar 4U 1901+03 observed with Insight-HXMT and NICER. Both spectra and pulse profiles evolve significantly in the decaying phase of the outburst. Dozens of flares are observed throughout the outburst. They are more frequent and brighter at the outburst peak. We find that the flares, which have a duration from tens to hundreds of seconds, are generally brighter than the persistent emission by a factor of $\sim$ 1.5. The pulse profile shape during the flares can be significantly different than that of the persistent emission. In particular, a phase shift is clearly observed in many cases. We interpret these findings as direct evidence of changes of the pulsed beam pattern, due to transitions between the sub- and super-critical accretion regimes on a short time scale. We also observe that at comparable luminosities the flares' pulse profiles are rather similar to those of the persistent emission. This indicates that the accretion on the polar cap of the neutron star is mainly determined by the luminosity, i.e., the mass accretion rate., 11 pages, 8 figures, accepted for publication in MNRAS
Published: 2020

43. Constraining the transient high-energy activity of FRB180916.J0158+65 with Insight-HXMT followup observations

Author: L. Chen, Yu-Dong Gu, Ya Fang Huang, R. J. Yang, Y. J. Yang, L. Wang, Junqiang Zhang, Wenhan Jiang, Qiu-Yi Luo, X. H. Liang, C. Z. Liu, G. C. Xiao, B. Y. Wu, Y. L. Tuo, Sisi Yang, He-Yang Liu, Wei Cui, W. S. Wang, Xiaobo Li, Wei Zhang, G. H. Gao, Ge Ou, Bing Li, B. B. Wu, Bin Meng, C. Guidorzi, F. Frontera, Yi Zhang, C. Cai, Luciano Nicastro, Lei Sun, Mauro Orlandini, M. Wu, J. Jin, Xin-Fu Zhao, H. S. Zhao, Y. Nang, Cheng-Cheng Guo, Y. P. Xu, Tao Luo, Yuan You, Qingcui Bu, S. Xiao, C. K. Li, Qi-Bin Yi, Shaolin Xiong, P. J. Wang, Wenxiong Li, Y. B. Chen, J. Y. Liao, H. M. Zhang, L. D. Kong, B. S. Liu, X. X. Li, H. Gao, H. W. Liu, N. Sai, Z. W. Li, W. C. Zhang, R. C. Ma, Min Gao, Fuqin Zhang, Y. F. Zhang, S. N. Zhang, D. K. Zhou, C. Wang, J. L. Qu, J. Guan, Lorenzo Amati, Y. G. Zheng, Y. S. Wang, Xin Ren, Tian-Xiang Chen, E. Virgilli, Lian Tao, Z. Chang, Da-Wei Han, Jia Huo, Y. H. Tan, X. Y. Song, X. F. Li, Gang Li, P. Zhang, Ming-Yu Ge, J. Y. Nie, Yuan-Yuan Du, F. J. Lu, XiangYang Wen, X. H. Ma, Li-Ming Song, Xue-Feng Lu, Tong Li, S. M. Jia, X. J. Liu, X. L. Cao, Q. Q. Yin, Y. P. Chen, S. J. Zheng, ITA, and CHN
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Socio-culturale, Context (language use), Astrophysics, Magnetar, 01 natural sciences, law.invention, Telescope, stars: magnetars, law, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Fast radio burst, Detector, Astronomy and Astrophysics, radiation mechanisms: non-thermal, stars: magnetars, radiation mechanisms: non-thermal, Wavelength, Space and Planetary Science, Phase space, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract: A link between magnetars and fast radio burst (FRB) sources has finally been established. In this context, one of the open issues is whether/which sources of extra galactic FRBs exhibit X/gamma-ray outbursts and whether it is correlated with radio activity. We aim to constrain possible X/gamma-ray burst activity from one of the nearest extragalactic FRB sources currently known over a broad energy range, by looking for bursts over a range of timescales and energies that are compatible with being powerful flares from extragalactic magnetars. We followed up the as-yet nearest extragalactic FRB source at a mere 149 Mpc distance, the periodic repeater FRB180916.J0158+65, during the active phase on February 4-7, 2020, with the Insight-Hard X-ray Modulation Telescope (HXMT). Taking advantage of the combination of broad band, large effective area, and several independent detectors available, we searched for bursts over a set of timescales from 1 ms to 1.024 s with a sensitive algorithm, that had previously been characterised and optimised. Moreover, through simulations we studied the sensitivity of our technique in the released energy-duration phase space for a set of synthetic flares and assuming different energy spectra. We constrain the possible occurrence of flares in the 1-100 keV energy band to E, 10 pages, 3 figures, accepted by A&A
Published: 2020

44. X-ray reprocessing in accreting pulsar GX 301-2 observed with Insight-HXMT

Author: G. H. Gao, X. X. Li, M. Wu, S. J. Zheng, Y. G. Zheng, Y. Nang, Mauro Orlandini, J. Y. Liao, H. M. Zhang, Y. L. Tuo, Y. J. Yang, R. C. Ma, Y. F. Zhang, X. B. Li, B. S. Liu, Yuan You, X. Q. Ren, Yanji Yang, Armin Nabizadeh, C. Cai, L. Chen, Tian-Xiang Chen, Wenxiong Li, Wan-Chang Zhang, W. S. Wang, Yi Zhang, Ge Ou, Andrea Santangelo, R. J. Yang, Bo Li, Peng Zhang, Qiu-Yi Luo, B. B. Wu, Cunguo Wang, H. S. Zhao, Li-Ming Song, Ming-Yu Ge, C. K. Li, F. J. Lu, Xue-Feng Lu, Y. P. Chen, Shuinai Zhang, Tong Li, Y. H. Tan, P. J. Wang, J. Y. Zhang, Victor Doroshenko, Shaolin Xiong, S. M. Jia, XiangYang Wen, Ling-Jun Wang, H. Gao, Jiren Liu, X. H. Ma, Z. W. Li, Yuan-Yuan Du, C. Z. Liu, D. K. Zhou, Sisi Yang, Ya Fang Huang, J. Jin, Xin-Fu Zhao, G. Li, Tao Luo, S. Xiao, Yu-Dong Gu, X. J. Liu, D. Gavran, X. L. Cao, Q. Q. Yin, Q. B. Yi, B. Y. Wu, V. F. Suleimanov, L. D. Kong, Y. B. Chen, X. H. Liang, L. Sun, Fuqin Zhang, S. N. Zhang, Long Ji, Z. Chang, Y. H. Zhang, Y. P. Xu, Wenhan Jiang, H. W. Liu, N. Sai, Y. S. Wang, W. C. Zhang, Xuelong Li, J. Guan, Lian Tao, Cheng-Cheng Guo, X. Y. Song, Jia Huo, Lorenzo Ducci, J. Y. Nie, Bin Meng, Wei Cui, G. C. Xiao, Qingcui Bu, Da-Wei Han, J. L. Qu, Hongfei Liu, ITA, DEU, and CHN
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Accretion (meteorology), Astrophysics::High Energy Astrophysical Phenomena, X-ray, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, 01 natural sciences, Neutron star, Pulsar, Space and Planetary Science, Ionization, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010306 general physics, Absorption (electromagnetic radiation), Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Equivalent width, Astrophysics::Galaxy Astrophysics
Abstract: We investigate the absorption and emission features in observations of GX 301-2 detected with Insight-HXMT/LE in 2017-2019. At different orbital phases, we found prominent Fe Kalpha, Kbeta and Ni Kalpha lines, as well as Compton shoulders and Fe K-shell absorption edges. These features are due to the X-ray reprocessing caused by the interaction between the radiation from the source and surrounding accretion material. According to the ratio of iron lines Kalpha and Kbeta, we infer the accretion material is in a low ionisation state. We find an orbital-dependent local absorption column density, which has a large value and strong variability around the periastron. We explain its variability as a result of inhomogeneities of the accretion environment and/or instabilities of accretion processes. In addition, the variable local column density is correlated with the equivalent width of the iron Kalpha lines throughout the orbit, which suggests that the accretion material near the neutron star is spherically distributed., Comment: 10 pages, 5 figures, 2 tables, accepted for publication in MNRAS
Published: 2020
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45. Prospects for a Multi-TeV Gamma-ray Sky Survey with the LHAASO Water Cherenkov Detector Array

Author: Guoqing Xiao, Bo Gao, Yu-Hua Yao, B. Q. Qiao, E. W. Liang, X. G. Wang, Yong Zhang, X. C. Chang, X. H. Cui, S. Wu, F. Y. Li, M. M. Ge, H. L. Dai, L. X. Bai, Z. G. Yao, Lei Zhao, Chang Jin, L. Chen, J. W. Zhao, H. D. Liu, Duo Yan, BZ Zhao, Z. X. Liu, Y. C. Nan, H. B. Li, H. K. Lv, B. D'Ettorre Piazzoli, W. X. Wu, Xiao-Yang Zhang, Y. D. Cheng, Z. H. Wang, F. R. Zhu, Y. Wang, M. Zha, P. Zhou, Yi Chen, C. X. Liu, Xufang Li, Yinong Liu, Jun-Jie Wei, Y. Y. Guo, R. Y. Liu, X. F. Wu, L. Zhang, X. J. Wang, H. M. Zhang, V. Rulev, Xiao-Hu Zhang, Y. Yu, C. Y. Wu, Zhe Cao, W. H. Huang, Guanghua Gong, Li-Sheng Geng, B. M. Chen, L. Xue, B. Liu, L. L. Yang, D. H. Huang, Y. A. Han, B. B. Zhang, D. M. Wei, Y. D. Cui, S. R. Zhang, Ziyi Wang, Zhengguo Cao, X. L. Ji, R. Lu, Jianrong Zhou, M. J. Yang, Z. Y. Pei, Y. M. Ye, S. P. Chao, H. C. Li, Jun He, Qiang Yuan, G. M. Xiang, Z. J. Jiang, Jiaxing Li, V. Alekseenko, J. F. Chang, Danzengluobu, H. Y. Jia, J. Chen, Zebo Tang, P. Pattarakijwanich, J. S. Liu, H. Y. Zhang, J. R. Mao, Wang Yanfang, H. Wang, D. Bastieri, Liang-Liang Wang, Jie Zhang, Teresa Montaruli, Cong Li, Y. Li, K. Levochkin, X. J. Bi, T. X. Zeng, Chao-Peng Wang, J. W. Zhang, S. Z. Chen, H. Liu, X. D. Sheng, Yu. V. Stenkin, C. Hou, H. Zhu, Z. K. Zeng, P. P. Zhang, P. F. Zhang, Wenwu Tian, W. J. Long, Lanqing Ma, G. G. Xin, S. H. Feng, X. Y. Wang, X. Zuo, J. C. Wang, W. H. Wang, R. Zhou, N. Yin, H. B. Hu, C. F. Feng, S. M. Liu, X. T. Huang, Yi Zhang, N. Cheng, Cheng Li, Ying Zhang, Hong-Jie Li, H. Li, Y. Zheng, M. L. Chen, Axikegu, S. B. Yang, S. W. Cui, F. Ji, J. H. Fan, Y. Z. Fan, Bo-Qiang Ma, C. W. Yang, L. Feng, Z. G. Dai, L. Z. Zhao, L. Q. Yin, Wang Yingjie, Wei Liu, Zujian Wang, Z. Li, W. Zeng, Shengxue Zhang, Q. B. Gou, Huihai He, M. H. Gu, J. Fang, X. L. Chen, H. G. Wang, O. Shchegolev, S. L. He, K. Jiang, F. Zheng, T. L. Chen, W. Gao, T. Wen, L. Shao, Yucheng Feng, M. Y. Qi, X. X. Zhou, Yiwei Wang, Felix Aharonian, K. Li, Y. F. Liang, Ruizhi Yang, Y. W. Bao, David Ruffolo, Z. Y. You, S. Hu, J. Y. Liu, Ming Chen, Warit Mitthumsiri, V. Stepanov, Q. An, Q. Gao, K. J. Zhu, Z. B. Sun, P. H. T. Tam, Y. Q. Guo, H. R. Wu, B. Z. Dai, D. Liu, M. Heller, Sina Chen, H. D. Zeng, X. H. You, Renxin Xu, C. G. Zhu, Minghui Liu, X. H. Ma, Y. He, J. R. Shi, Yuan-Ming Xing, F. F. Yang, X. X. Li, W. L. Li, Q. H. Chen, D. della Volpe, Huang Qiyan, A. Masood, H. Cai, and Alejandro Sáiz
Subjects: Nuclear and High Energy Physics, Active galactic nucleus, Cherenkov detector, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, High Energy Physics - Experiment, law.invention, Hochenergie-Astrophysik Theorie - Abteilung Hinton, High Energy Physics - Experiment (hep-ex), Observatory, law, 0103 physical sciences, 010306 general physics, Instrumentation, media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Order (ring theory), Astronomy and Astrophysics, Projection (relational algebra), Air shower, Sky, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract: The Water Cherenkov Detector Array (WCDA) is a major component of the Large High Altitude Air Shower Array Observatory (LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. The WCDA is aimed at the study of TeV $\gamma$-rays. In order to evaluate the prospects of searching for TeV $\gamma$-ray sources with the WCDA, we present in this paper a projection for the one-year sensitivity of the WCDA to TeV $\gamma$-ray sources from TeVCat (footnote: http://tevcat.uchicago.edu) using an all-sky approach. Out of 128 TeVCat sources observable to the WCDA up to a zenith angle of $45^\circ$, we estimate that 42 would be detectable for one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei (AGN)., Comment: 10 pages,10 figures, it is to be published in Chinese Physics C
Published: 2020
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46. Absolute calibration of LHAASO WFCTA camera based on LED

Author: W. J. Long, Rong Xu, Cong Li, J. J. Xia, Houdun Zeng, Axikegu, Yongchun Wang, H. H. He, Xufang Li, X. X. Zhai, Y. D. Cui, L. Feng, H. B. Li, F. R. Zhu, Qie Sun, Yi Chen, F. Y. Li, C. F. Feng, D. H. Huang, Bin Zhou, J. Y. Shi, V. I. Stepanov, H. Zhu, Jun-Jie Wei, L. Z. Zhao, F. Ji, M. Zha, Jia Zhang, Y. H. Yao, Yi Zhang, B. Q. Qiao, Rui Zhang, Linbin Yang, Zhengguo Cao, M. L. Chen, Jianeng Zhou, Jian Wang, Chiming Jin, Zhe Cao, M. M. Ge, X. Zuo, Xuliang Chen, D.A. Kuleshov, Hong-Guang Wang, Y. He, Xiang-Yu Wang, E. S. Chen, Y. A. Han, N. Cheng, J. Fang, S. Hu, J. Y. Liu, G. M. Xiang, H. C. Song, S. P. Zhao, Zebo Tang, H. B. Xiao, W. Liu, L. X. Bai, Binyu Zhao, Yun-Feng Liang, Tao Zeng, Jixia Li, W. Zeng, Bin Ma, Donglian Xu, Z. Min, Xuelong Wang, Xiaofei Zhang, X. L. Guo, X. J. Dong, Hefan Li, S. H. Feng, Q. H. Chen, G. G. Xin, Warit Mitthumsiri, Kai-Kai Duan, Ying Zhang, P. F. Zhang, Z. X. Wang, H.Y. Gan, T. Wen, S. W. Cui, K. Levochkin, Hao Zhou, W. Wang, P. Pattarakijwanich, Kun Fang, D. M. Wei, H. Cai, S. Wu, Sina Chen, X. D. Sheng, Minghao Qi, C. X. Liu, Y. L. Feng, D. Bastieri, Q. An, B. Y. Pang, B. Liu, B. D. Wang, T. Ke, S. B. Yang, Bai Yibing, Lidan Gao, Y. W. Bao, Y. C. Nan, S. Z. Chen, Zhe Li, Shi-Qi Hu, X. H. You, H. B. Hu, H. Liu, X. T. Huang, J. C. He, Bingshui Gao, R. Zhou, L. Y. Wang, Z. H. Wang, Li Zhang, Z. G. Dai, M. J. Yang, Fan Yang, A. Masood, David Ruffolo, C. W. Yang, Q. Gao, Jun Liu, Z. K. Zeng, C. D. Gao, Lei Zhao, Z. C. Huang, B. B. Li, G. H. Gong, Lang Shao, M. J. Chen, Y. J. Wang, H. M. Zhang, D. della Volpe, He Zhang, Jianguo Qin, Y. J. Bi, Jun-Hui Fan, H. D. Liu, W. H. Huang, Y. D. Cheng, Z. B. Sun, Bo Zhang, Duo Yan, Z. X. Liu, Ruizhi Yang, X. N. Sun, Li-Sheng Geng, S. L. He, W. L. Li, Y. P. Wang, Y. H. Yu, Z. G. Yao, D. X. Xiao, J.W. Xia, X. G. Wang, H. L. Dai, Y. Y. Guo, Danzengluobu, Y. Q. Qi, H. Wang, W. Gao, Yi Liu, J. B. Zhao, Y. K. Hor, J. Chen, Zheng Wang, Q. B. Gou, L. P. Wang, Qizhi Huang, T. L. Chen, X. F. Wu, X. L. Ji, R. Lu, Cheng Guang Zhu, Zhuo Li, T. Montaruli, S. Q. Xi, Zhen Wang, Y.T. Fu, G. C. Xiao, Y. Z. Fan, X. H. Cui, Z. Y. Pei, B. D'Ettorre Piazzoli, W. X. Wu, H. Y. Jia, Y. Wang, B. Z. Dai, Alejandro Sáiz, Youping Li, J. T. Cai, R. Liu, Long Chen, Y. J. Wei, Fengqin Guo, J. F. Chang, V. Rulev, L. Xue, Liang Chen, Y. L. Xin, Yugang Zhang, Xinbo He, K. Jiang, X. J. Bi, X. J. Hu, Y. Zheng, L. Q. Yin, X. Y. Huang, J. W. Zhang, P. P. Zhang, Wenwu Tian, Pak-Hin Thomas Tam, H. C. Li, Z. X. Fan, Z. Y. You, J. Y. Yang, Ping Zhou, Junjie Mao, Y. Z. Li, F. Zheng, Y. Q. Guo, H. R. Wu, B. M. Chen, X. X. Zhou, Q. Yuan, Felix Aharonian, H. N. He, M. Heller, K. Li, L. L. Ma, Yu. V. Stenkin, Z. J. Jiang, J. Liu, Yong Zhang, R. N. Wang, C. Hou, Shuibin Lin, S. M. Liu, Lu Zhang, J. S. Wang, Cunguo Wang, E. W. Liang, N. Yin, K. J. Zhu, Minghui Liu, Shengxue Zhang, Cheng Li, Dong Liu, Jinyao Liu, C. Y. Wu, Y. M. Ye, Yunchao Liu, Y. M. Xing, H. K. Lv, X. H. Ma, Xiang Zhang, Y. Su, J. G. Guo, S. R. Zhang, M. H. Gu, L. X. Zhang, Jiawei Yan, Xin Li, and Oleg Shchegolev
Subjects: Physics, Nuclear and High Energy Physics, Photon, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Metrology, law.invention, Telescope, Air shower, Silicon photomultiplier, Optics, law, Calibration, business, Instrumentation, Cherenkov radiation
Abstract: The main scientific goal of the LHAASO WFCTA experiment is to measure the cosmic ray energy spectra and composition from 10 TeV to 1 EeV. Cherenkov photons in the extensive air shower measured by the SiPM camera of Cherenkov telescopes can be used to reconstruct the cosmic ray energy. The absolute calibration of the camera is a crucial step to achieve the accurate measurement of the cosmic ray energy spectrum. A multi-wavelength cylindrical illuminator based on LEDs is developed and mounted inside the telescope to calibrate and monitor the camera, and the illuminator’s stability is better than 0.5% under the temperature variation from -26 to 26 ° C. A portable probe with a single photoelectron resolution of 21.6% is developed. After calibration by National Institute of Metrology, China (NIM), the probe is taken to the LHAASO site to measure the absolute photon density of the cylindrical illuminator inside the telescope. Based on the illuminator with known photon density, the photon conversion factor of the camera can be calibrated, and the overall calibration uncertainty is less than 2.6%.
Published: 2022
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47. FAST Globular Cluster Pulsar Survey: Twenty-four Pulsars Discovered in 15 Globular Clusters

Author: J. Luo, Kuo Liu, Zhichen Pan, Lei Qian, Scott M. Ransom, X. H. Ma, Peng Jiang, Di Li, Zhen Yan, Lin Wang, and Duncan R. Lorimer
Subjects: Radio telescope, Physics, Pulsar, Space and Planetary Science, Globular cluster, Astronomy and Astrophysics, Astrophysics
Published: 2021
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48. Absolute-energy-scale calibration of ARGO-YBJ for light primaries in multi-TeV region with the Moon shadow observation

Author: X. C. Yang, H. H. He, T. Di Girolamo, Zhenyong Feng, H. Y. Jia, B. D'Ettorre Piazzoli, L. Xue, Hong-peng Lu, P. Pistilli, H. M. Zhang, X. X. Zhou, M. Iacovacci, M. Zha, Labaciren, X. D. Sheng, S. M. Mari, J. K. K. Liu, A. Surdo, Paolo Bernardini, L. L. Ma, Haibing Hu, Longzhou Zhang, H. W. Wang, J. B. Zhao, P. Salvini, Chang-Chun Ning, C. X. Liu, H. J. Li, H. R. Wu, Zhaoyang Feng, G. Marsella, X. J. Bi, Y. Zhang, Z. G. Yao, G. Mancarella, Zhaxisangzhu, C. Y. Wu, B. Bartoli, S. Z. Chen, L. Perrone, R. Santonico, G. Di Sciascio, Y. H. Tan, Fudong Shi, B. Z. Dai, S. Mastroianni, Carlo Vigorito, Zhaxiciren, F. R. Zhu, Danzengluobu, Y. Q. Guo, Q. Q. Zhu, I. De Mitri, Q. B. Gou, Zihuang Cao, Piero Vallania, T. L. Chen, A. F. Yuan, Pengnian Shen, S. Catalanotti, S. W. Cui, Hongbo Hu, C. F. Feng, P. Montini, X. H. Ma, X. Y. Zhang, Minghui Liu, R. Iuppa, S. Vernetto, A. D'Amone, Q. Y. Yang, Bartoli, B., Bernardini, P., Bi, X. J., Cao, Z., Catalanotti, S., Chen, S. Z., Chen, T. L., Cui, S. W., Dai, B. Z., D'Amone, A., Danzengluobu, Null, De Mitri, I., D'Ettorre Piazzoli, B., Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, M., Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, Stefano Maria, Marsella, G., Mastroianni, S., Montini, Paolo, Ning, C. C., Perrone, L., Pistilli, Pio, Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M, Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Bernardini, Paolo, D'Amone, Antonio, DE MITRI, Ivan, D’Ettorre Piazzoli, B., Mancarella, Giovanni, Mari, S. M., Marsella, Giovanni, Montini, P., Perrone, Lorenzo, Pistilli, P., Zha, M., and collaboration), (The ARGO YBJ
Subjects: Cosmic ray, Energy calibration, Energy spectrum, Moon shadow, Physics, Large Hadron Collider, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Moon shadow, Astronomy, Astronomy and Astrophysics, Cosmic ray, Interaction model, Astrophysics, 01 natural sciences, Scale error, Energy calibration, Energy spectrum, Rigidity (electromagnetism), 0103 physical sciences, Ultra-high-energy cosmic ray, 010303 astronomy & astrophysics, Argo
Abstract: In 2011 ARGO-YBJ experiment has reported a work to study the absolute rigidity scale of the primary cosmic ray particles based on the Moon's shadow observation. Given the progress in high energy hadronic interaction models with LHC data, in cosmic ray chemical composition measurement and in experimental data accumulation, more updates can be researched. This paper aims to further disentangle the composition dependence in absolute-energy-scale calibration by using specific moon-shadow data which mainly is comprised of light component cosmic rays. Results show that, 17% energy scale error is estimated from 3 TeV to 50 TeV. To validate the performance of this technique, the light component cosmic ray spectrum in the same energy region is shown. (C) 2017 Elsevier B.V. All rights reserved.
Published: 2017
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49. Intrinsic linearity of bakelite Resistive Plate Chambers operated in streamer mode

Author: M. Iacovacci, L. L. Ma, X. H. Ma, Hongbo Hu, X. Y. Zhang, Minghui Liu, L. Perrone, Zihuang Cao, P. Creti, Haifeng Li, R. Santonico, Yicheng Guo, J. B. Zhao, P. Salvini, A. Budano, Chang-Chun Ning, Cunfeng Feng, Zhaoyang Feng, Fudong Shi, Z. G. Yao, C. Y. Wu, B. D'Ettorre Piazzoli, H. Lu, F. R. Zhu, S. Mastroianni, Danzengluobu, G. Di Sciascio, I. De Mitri, S. M. Mari, X. C. Yang, Piero Vallania, T. L. Chen, Zhaxiciren, G. Liguori, L. Xue, Paolo Camarri, Zhenyong Feng, B. Bartoli, C. X. Liu, H. W. Wang, Zhaxisangzhu, J. K. K. Liu, H. Y. Jia, Longzhou Zhang, Q. Q. Zhu, M. Zha, X. J. Bi, M. Panareo, G. Mancarella, S. W. Cui, S. Z. Chen, T. Di Girolamo, H. R. Wu, B. Z. Dai, F. Ruggieri, P. Branchini, Q. B. Gou, A. F. Yuan, Labaciren, Q. Y. Yang, G. Zizzi, H. H. He, Y. H. Tan, A. D'Amone, X. D. Sheng, Paolo Bernardini, Paolo Montini, R. Iuppa, R. Cardarelli, G. Marsella, S. Vernetto, Pengnian Shen, S. Catalanotti, P. Pistilli, H. M. Zhang, X. X. Zhou, A. Surdo, Carlo Vigorito, Haibing Hu, Y. Zhang, D. Martello, Bartoli B., Bernardini P., Bi X. J., Branchini P., Budano A., Camarri P., Cao Z., Cardarelli R., Catalanotti S., Chen S. Z., Chen T. L., Creti P., Cui S. W., Dai B. Z., D'Amone A., Danzengluobu, De Mitri I., D'Ettorre Piazzoli B., Di Girolamo T., Di Sciascio G., Feng C. F., Feng Z., Gou Q. B., Guo Y. Q., He H. H., Hu H., Iacovacci M., Iuppa R., Jia H. Y., Labaciren, Li H. J., Liguori G., Liu C., Liu J., Liu M. Y., Lu H., Ma L. L., Ma X. H., Mancarella G., Mari S. M., Marsella G., Martello D., Mastroianni S., Montini P., Ning C. C., Panareo M., Perrone L., Pistilli P., Ruggieri F., Salvini P., Santonico R., Shen P. R., Sheng X. D., Shi F., Surdo A., Tan Y. H., Vallania P., Vernetto S., Vigorito C., Wang H., Wu C. Y., Wu H. R., Xue L., Yang Q. Y., Yang X. C., Yao Z. G., Yuan A. F., Zha M., Zhang H. M., Zhang L., Zhang X. Y., Zhang Y., Zhao J., Zhaxiciren Zhaxisangzhu, Zhou X. X., Zhu F. R., Zhu Q. Q., Zizzi G., Bartoli, B., Bernardini, P., Bi, X. J., Branchini, P., Budano, A., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, S., Chen, S. Z., Chen, T. L., Creti, P., Cui, S. W., Dai, B. Z., D'Amone, A., De Mitri, I., D'Ettorre Piazzoli, B., Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Z., Gou, Q. B., Guo, Y. Q., He, H. H., Hu, H., Iacovacci, M., Iuppa, R., Jia, H. Y., Li, H. J., Liguori, G., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Panareo, M., Perrone, L., Pistilli, P., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Zhaxisangzhu, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., D’Amone, A., Danzengluobu, Null, D’Ettorre Piazzoli, B., Feng, Zhaoyang, Feng, Zhenyong, Hu, Haibing, Hu, Hongbo, Labaciren, Null, Zhaxiciren, Null, and Zhaxisangzhu, Null
Subjects: Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Intrinsic linearity, Streamer mode, Cosmic ray, Calorimetry, 01 natural sciences, chemistry.chemical_compound, Optics, 0103 physical sciences, Bakelite, Particle density, 010303 astronomy & astrophysics, Instrumentation, Physics, Resistive touchscreen, 010308 nuclear & particles physics, business.industry, Detector, Settore FIS/01 - Fisica Sperimentale, Linearity, RPC detector, Streamer mode, Intrinsic linearity, Calorimetry, chemistry, Particle, Physics::Accelerator Physics, RPC detector, business, Beam (structure)
Abstract: Resistive Plate Chambers have largely been used in High Energy Physics and Cosmic Ray research. In view of using this detector for calorimetry applications it is important to know the maximum measurable particle density, or its intrinsic linearity limit, which is tightly related to the dimension of the discharge region. In this paper we report the results of measurements performed at the Beam Test Facility (INFN National Laboratory of Frascati, Italy) where the intrinsic linearity of bakelite RPCs operated in streamer mode has been tested at different impinging particle densities.
Published: 2019

50. Hot disk of the Swift J0243.6+6124 revealed by Insight-HXMT

Author: J. K. Deng, X. H. Ma, B. B. Wu, Min Gao, Lian Tao, L. Chen, Yi-Yan Yang, X. Y. Song, C. L. Zhang, Xue-Feng Lu, Shuinai Zhang, H. S. Zhao, S. M. Jia, C. Z. Liu, M. X. Fu, Y. Nang, Ya Fang Huang, Tao Luo, Wan-Chang Zhang, Bin Meng, Mao-Shun Li, Sisi Yang, X. X. Li, L. J. Qu, J. Z. Wang, Y. L. Tuo, G. F. Wang, J. W. Yang, W. C. Jiang, Tian-Xiang Chen, Weiguang Cui, Qingcui Bu, Yunchao Liu, Y. J. Jin, L. M. Song, Sergey S. Tsygankov, Y. J. Yang, V. Doroshenko, Ti-Pei Li, F. Zhang, Yuan-Yuan Du, S. J. Zheng, Gang Chen, W. S. Wang, J. Y. Liao, H. M. Zhang, Junke Zhang, Wenxiong Li, Qing-He Zhang, Ge Ou, Da-Wei Han, XiangYang Wen, J. Y. Nie, Y. F. Zhang, Andrea Santangelo, Shaolin Xiong, Bo Lu, J. Jin, Y. J. Zhang, Xuchao Zhao, H. Gao, W. Z. Zhang, Wei Zhang, G. H. Gao, Yi-Qiao Dong, Y. H. Tan, Cheng-Cheng Guo, M. Wu, Y. Zhang, Fangjun Lu, Y. B. Chen, Alexander A. Mushtukov, Z. Zhang, Long Ji, Y. P. Chen, Bing Li, Y. S. Wang, T. Zhang, Chun-sheng Zhang, Xiaobo Li, W. Hu, X. F. Li, X. H. Liang, C. L. Zou, Z. L. Zhang, C. K. Li, G. C. Xiao, H. Xu, Y. X. Zhu, Z. W. Li, Ming-Yu Ge, Z. J. Li, ShaoZhen Liu, L. D. Kong, Yidong Xu, Yu-Dong Gu, S. N. Zhang, Jia Huo, Gang Li, X. L. Cao, J. Zhao, J. Guan, Aimei Zhang, GuoQing Liu, Wei Cui, Yu-Xuan Zhu, X. J. Liu, Liang Sun, Y. G. Li, Luhua Jiang, Z. Chang, Yujuan Liu, H. W. Liu, and N. Sai
Subjects: Swift, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Magnetosphere, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, computer.programming_language, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Scattering, Spectral properties, Astronomy and Astrophysics, Accretion (astrophysics), Neutron star, Radiation pressure, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, computer
Abstract: We report on analysis of observations of the bright transient X-ray pulsar \src obtained during its 2017-2018 giant outburst with Insight-HXMT, \emph{NuSTAR}, and \textit{Swift} observatories. We focus on the discovery of a sharp state transition of the timing and spectral properties of the source at super-Eddington accretion rates, which we associate with the transition of the accretion disk to a radiation pressure dominated (RPD) state, the first ever directly observed for magnetized neutron star. This transition occurs at slightly higher luminosity compared to already reported transition of the source from sub- to super-critical accretion regime associate with onset of an accretion column. We argue that this scenario can only be realized for comparatively weakly magnetized neutron star, not dissimilar to other ultra-luminous X-ray pulsars (ULPs), which accrete at similar rates. Further evidence for this conclusion is provided by the non-detection of the transition to the propeller state in quiescence which strongly implies compact magnetosphere and thus rules out magnetar-like fields., Submitted to MNRAS
Published: 2019
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